<?xml version="1.0" encoding="UTF-8"?>
<!--
    manpage, user manual, usage: VBoxManage modifyvm
-->
<!--
    Copyright (C) 2006-2023 Oracle and/or its affiliates.

    This file is part of VirtualBox base platform packages, as
    available from https://www.virtualbox.org.

    This program is free software; you can redistribute it and/or
    modify it under the terms of the GNU General Public License
    as published by the Free Software Foundation, in version 3 of the
    License.

    This program is distributed in the hope that it will be useful, but
    WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
    General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program; if not, see <https://www.gnu.org/licenses>.

    SPDX-License-Identifier: GPL-3.0-only
-->
<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"
  "http://www.oasis-open.org/docbook/xml/4.5/docbookx.dtd"[
<!ENTITY % all.entities SYSTEM "all-entities.ent">
%all.entities;
]>
<refentry id="vboxmanage-modifyvm" lang="en">
  <refentryinfo>
    <pubdate>$Date: 2024-02-19 16:32:13 +0100 (Mon, 19 Feb 2024) $</pubdate>
    <title>VBoxManage modifyvm</title>
  </refentryinfo>

  <refmeta>
    <refentrytitle>VBoxManage-modifyvm</refentrytitle>
    <manvolnum>1</manvolnum>
  </refmeta>

  <refnamediv>
    <refname>VBoxManage-modifyvm</refname>
    <refpurpose>Change settings for a virtual machine that is stopped</refpurpose>
    <refclass>&product-name;</refclass>
  </refnamediv>

  <refsynopsisdiv>
    <cmdsynopsis id="synopsis-vboxmanage-modifyvm-general">
<!-- The 'id' is mandatory and must start with 'synopsis-'. -->
      <command>VBoxManage modifyvm</command>
      <group choice="req">
        <arg choice="plain"><replaceable>uuid</replaceable></arg>
        <arg choice="plain"><replaceable>vmname</replaceable></arg>
      </group>
      <arg>--name=<replaceable>name</replaceable></arg>
      <arg>--groups= <arg choice="plain"><replaceable>group</replaceable> [,<replaceable>group</replaceable>...]</arg></arg>
      <arg>--description=<replaceable>description</replaceable></arg>
      <arg>--os-type=<replaceable>OS-type</replaceable></arg>
      <arg>--icon-file=<replaceable>filename</replaceable></arg>
      <arg>--memory=<replaceable>size-in-MB</replaceable></arg>
      <arg>--page-fusion=<group choice="plain">
          <arg choice="plain">on</arg>
          <arg choice="plain">off</arg>
        </group></arg>
      <arg>--vram=<replaceable>size-in-MB</replaceable></arg>
      <arg>--acpi=<group choice="plain">
          <arg choice="plain">on</arg>
          <arg choice="plain">off</arg>
        </group></arg>
      <arg>--ioapic=<group choice="plain">
          <arg choice="plain">on</arg>
          <arg choice="plain">off</arg>
        </group></arg>
      <arg>--hardware-uuid=<replaceable>UUID</replaceable></arg>
      <arg>--cpus=<replaceable>CPU-count</replaceable></arg>
      <arg>--cpu-hotplug=<group choice="plain">
          <arg choice="plain">on</arg>
          <arg choice="plain">off</arg>
        </group></arg>
      <arg>--plug-cpu=<replaceable>CPU-ID</replaceable></arg>
      <arg>--unplug-cpu=<replaceable>CPU-ID</replaceable></arg>
      <arg>--cpu-execution-cap=<replaceable>number</replaceable></arg>
      <arg>--pae=<group choice="plain">
          <arg choice="plain">on</arg>
          <arg choice="plain">off</arg>
        </group></arg>
      <arg>--long-mode=<group choice="plain">
          <arg choice="plain">on</arg>
          <arg choice="plain">off</arg>
        </group></arg>
      <arg>--ibpb-on-vm-exit=<group choice="plain">
          <arg choice="plain">on</arg>
          <arg choice="plain">off</arg>
        </group></arg>
      <arg>--ibpb-on-vm-entry=<group choice="plain">
          <arg choice="plain">on</arg>
          <arg choice="plain">off</arg>
        </group></arg>
      <arg>--spec-ctrl=<group choice="plain">
          <arg choice="plain">on</arg>
          <arg choice="plain">off</arg>
        </group></arg>
      <arg>--l1d-flush-on-sched=<group choice="plain">
          <arg choice="plain">on</arg>
          <arg choice="plain">off</arg>
        </group></arg>
      <arg>--l1d-flush-on-vm-entry=<group choice="plain">
          <arg choice="plain">on</arg>
          <arg choice="plain">off</arg>
        </group></arg>
      <arg>--mds-clear-on-sched=<group choice="plain">
          <arg choice="plain">on</arg>
          <arg choice="plain">off</arg>
        </group></arg>
      <arg>--mds-clear-on-vm-entry=<group choice="plain">
          <arg choice="plain">on</arg>
          <arg choice="plain">off</arg>
        </group></arg>
      <arg>--cpu-profile=<group choice="plain">
          <arg choice="plain">host</arg>
          <arg choice="plain">Intel 8086</arg>
          <arg choice="plain">Intel 80286</arg>
          <arg choice="plain">Intel 80386</arg>
        </group></arg>
      <arg>--hpet=<group choice="plain">
          <arg choice="plain">on</arg>
          <arg choice="plain">off</arg>
        </group></arg>
      <arg>--hwvirtex=<group choice="plain">
          <arg choice="plain">on</arg>
          <arg choice="plain">off</arg>
        </group></arg>
      <arg>--triple-fault-reset=<group choice="plain">
          <arg choice="plain">on</arg>
          <arg choice="plain">off</arg>
        </group></arg>
      <arg>--apic=<group choice="plain">
          <arg choice="plain">on</arg>
          <arg choice="plain">off</arg>
        </group></arg>
      <arg>--x2apic=<group choice="plain">
          <arg choice="plain">on</arg>
          <arg choice="plain">off</arg>
        </group></arg>
      <arg>--paravirt-provider=<group choice="plain">
          <arg choice="plain">none</arg>
          <arg choice="plain">default</arg>
          <arg choice="plain">legacy</arg>
          <arg choice="plain">minimal</arg>
          <arg choice="plain">hyperv</arg>
          <arg choice="plain">kvm</arg>
        </group></arg>
      <arg>--paravirt-debug= <arg choice="plain"><replaceable>key</replaceable>=<replaceable>value</replaceable> [,<replaceable>key</replaceable>=<replaceable>value</replaceable>...]</arg></arg>
      <arg>--nested-paging=<group choice="plain">
          <arg choice="plain">on</arg>
          <arg choice="plain">off</arg>
        </group></arg>
      <arg>--large-pages=<group choice="plain">
          <arg choice="plain">on</arg>
          <arg choice="plain">off</arg>
        </group></arg>
      <arg>--vtx-vpid=<group choice="plain">
          <arg choice="plain">on</arg>
          <arg choice="plain">off</arg>
        </group></arg>
      <arg>--vtx-ux=<group choice="plain">
          <arg choice="plain">on</arg>
          <arg choice="plain">off</arg>
        </group></arg>
      <arg>--nested-hw-virt=<group choice="plain">
          <arg choice="plain">on</arg>
          <arg choice="plain">off</arg>
        </group></arg>
      <arg>--virt-vmsave-vmload=<group choice="plain">
          <arg choice="plain">on</arg>
          <arg choice="plain">off</arg>
        </group></arg>
      <arg>--accelerate-3d=<group choice="plain">
          <arg choice="plain">on</arg>
          <arg choice="plain">off</arg>
        </group></arg>
      <arg>--accelerate-2d-video=<group choice="plain">
          <arg choice="plain">on</arg>
          <arg choice="plain">off</arg>
        </group></arg>
      <arg>--chipset=<group choice="plain">
          <arg choice="plain">ich9</arg>
          <arg choice="plain">piix3</arg>
        </group></arg>
    <arg>--iommu=<group choice="plain">
        <arg choice="plain">none</arg>
        <arg choice="plain">automatic</arg>
        <arg choice="plain">amd</arg>
        <arg choice="plain">intel</arg>
      </group></arg>
    <arg>--tpm-type=<group choice="plain">
        <arg choice="plain">none</arg>
        <arg choice="plain">1.2</arg>
        <arg choice="plain">2.0</arg>
        <arg choice="plain">host</arg>
        <arg choice="plain">swtpm</arg>
      </group></arg>
      <arg>--tpm-location=<group choice="plain">
          <arg choice="plain"><replaceable>location</replaceable></arg>
        </group></arg>
      <arg>--bios-logo-fade-in=<group choice="plain">
          <arg choice="plain">on</arg>
          <arg choice="plain">off</arg>
        </group></arg>
      <arg>--bios-logo-fade-out=<group choice="plain">
          <arg choice="plain">on</arg>
          <arg choice="plain">off</arg>
        </group></arg>
      <arg>--bios-logo-display-time=<replaceable>msec</replaceable></arg>
      <arg>--bios-logo-image-path=<replaceable>pathname</replaceable></arg>
      <arg>--bios-boot-menu=<group choice="plain">
          <arg choice="plain">disabled</arg>
          <arg choice="plain">menuonly</arg>
          <arg choice="plain">messageandmenu</arg>
        </group></arg>
      <arg>--bios-apic=<group choice="plain">
          <arg choice="plain">disabled</arg>
          <arg choice="plain">apic</arg>
          <arg choice="plain">x2apic</arg>
        </group></arg>
      <arg>--bios-system-time-offset=<replaceable>msec</replaceable></arg>
      <arg>--bios-pxe-debug=<group choice="plain">
          <arg choice="plain">on</arg>
          <arg choice="plain">off</arg>
        </group></arg>
      <arg>--system-uuid-le=<group choice="plain">
          <arg choice="plain">on</arg>
          <arg choice="plain">off</arg>
        </group></arg>
      <arg>--boot<replaceable>X</replaceable>=<group choice="plain">
          <arg choice="plain">none</arg>
          <arg choice="plain">floppy</arg>
          <arg choice="plain">dvd</arg>
          <arg choice="plain">disk</arg>
          <arg choice="plain">net</arg>
        </group></arg>
      <arg>--rtc-use-utc=<group choice="plain">
          <arg choice="plain">on</arg>
          <arg choice="plain">off</arg>
        </group></arg>
      <arg>--graphicscontroller=<group choice="plain">
          <arg choice="plain">none</arg>
          <arg choice="plain">vboxvga</arg>
          <arg choice="plain">vmsvga</arg>
          <arg choice="plain">vboxsvga</arg>
        </group></arg>
      <arg>--snapshot-folder=<group choice="plain">
          <arg choice="plain">default</arg>
          <arg choice="plain"><replaceable>pathname</replaceable></arg>
        </group></arg>
      <arg>--firmware=<group choice="plain">
          <arg choice="plain">bios</arg>
          <arg choice="plain">efi</arg>
          <arg choice="plain">efi32</arg>
          <arg choice="plain">efi64</arg>
        </group></arg>
      <arg>--guest-memory-balloon=<replaceable>size-in-MB</replaceable></arg>
      <arg>--default-frontend=<group choice="plain">
          <arg choice="plain">default</arg>
          <arg choice="plain"><replaceable>name</replaceable></arg>
        </group></arg>
<!-- There are currently undocumented options &#45;&#45;iocache and
&#45;&#45;iocachesize which are scheduled for removal. Not worth spending
time on documenting it. -->
      <arg>--vm-process-priority=<group choice="plain">
          <arg choice="plain">default</arg>
          <arg choice="plain">flat</arg>
          <arg choice="plain">low</arg>
          <arg choice="plain">normal</arg>
          <arg choice="plain">high</arg>
        </group></arg>
    </cmdsynopsis>

    <cmdsynopsis id="synopsis-vboxmanage-modifyvm-networking">
      <command>VBoxManage modifyvm</command>
      <group choice="req">
        <arg choice="plain"><replaceable>uuid</replaceable></arg>
        <arg choice="plain"><replaceable>vmname</replaceable></arg>
      </group>
      <arg>--nic<replaceable>N</replaceable>=<group choice="plain">
          <arg choice="plain">none</arg>
          <arg choice="plain">null</arg>
          <arg choice="plain">nat</arg>
          <arg choice="plain">bridged</arg>
          <arg choice="plain">intnet</arg>
          <arg choice="plain">hostonly</arg>
          <arg choice="plain">hostonlynet</arg>
          <arg choice="plain">generic</arg>
          <arg choice="plain">natnetwork</arg>
          <arg choice="plain">cloud</arg>
        </group></arg>
      <arg>--nic-type<replaceable>N</replaceable>=<group choice="plain">
          <arg choice="plain">Am79C970A</arg>
          <arg choice="plain">Am79C973</arg>
          <arg choice="plain">82540EM</arg>
          <arg choice="plain">82543GC</arg>
          <arg choice="plain">82545EM</arg>
          <arg choice="plain">virtio</arg>
        </group></arg>
      <arg>--cable-connected<replaceable>N</replaceable>=<group choice="plain">
          <arg choice="plain">on</arg>
          <arg choice="plain">off</arg>
        </group></arg>
      <arg>--nic-trace<replaceable>N</replaceable>=<group choice="plain">
          <arg choice="plain">on</arg>
          <arg choice="plain">off</arg>
        </group></arg>
      <arg>--nic-trace-file<replaceable>N</replaceable>=<replaceable>filename</replaceable></arg>
      <arg>--nic-property<replaceable>N</replaceable>=<replaceable>name</replaceable>= <arg><replaceable>value</replaceable></arg></arg>
      <arg>--nic-speed<replaceable>N</replaceable>=<replaceable>kbps</replaceable></arg>
      <arg>--nic-boot-prio<replaceable>N</replaceable>=<replaceable>priority</replaceable></arg>
      <arg>--nic-promisc<replaceable>N</replaceable>=<group choice="plain">
          <arg choice="plain">deny</arg>
          <arg choice="plain">allow-vms</arg>
          <arg choice="plain">allow-all</arg>
        </group></arg>
      <arg>--nic-bandwidth-group<replaceable>N</replaceable>=<group choice="plain">
          <arg choice="plain">none</arg>
          <arg choice="plain"><replaceable>name</replaceable></arg>
        </group></arg>
      <arg>--bridge-adapter<replaceable>N</replaceable>=<group choice="plain">
          <arg choice="plain">none</arg>
          <arg choice="plain"><replaceable>device-name</replaceable></arg>
        </group></arg>
      <arg>--cloud-network<replaceable>N</replaceable>=<replaceable>network-name</replaceable></arg>
      <arg>--host-only-adapter<replaceable>N</replaceable>=<group choice="plain">
          <arg choice="plain">none</arg>
          <arg choice="plain"><replaceable>device-name</replaceable></arg>
        </group></arg>
      <arg>--host-only-net<replaceable>N</replaceable>=<replaceable>network-name</replaceable></arg>
      <arg>--intnet<replaceable>N</replaceable>=<replaceable>network-name</replaceable></arg>
      <arg>--nat-network<replaceable>N</replaceable>=<replaceable>network-name</replaceable></arg>
      <arg>--nic-generic-drv<replaceable>N</replaceable>=<replaceable>driver-name</replaceable></arg>
      <arg>--mac-address<replaceable>N</replaceable>=<group choice="plain">
          <arg choice="plain">auto</arg>
          <arg choice="plain"><replaceable>MAC-address</replaceable></arg>
        </group></arg>
    </cmdsynopsis>

    <cmdsynopsis id="synopsis-vboxmanage-modifyvm-networking-nat">
      <command>VBoxManage modifyvm</command>
      <group choice="req">
        <arg choice="plain"><replaceable>uuid</replaceable></arg>
        <arg choice="plain"><replaceable>vmname</replaceable></arg>
      </group>
      <arg>--nat-net<replaceable>N</replaceable>=<group choice="plain">
          <arg choice="plain"><replaceable>network</replaceable></arg>
          <arg choice="plain">default</arg>
        </group></arg>
      <arg>--nat-pf<replaceable>N</replaceable>=<group choice="plain">
          <arg choice="plain">[<replaceable>rule-name</replaceable>],tcp</arg>
          <arg choice="plain">udp,[<replaceable>host-IP</replaceable>],<replaceable>hostport</replaceable>,[<replaceable>guest-IP</replaceable>],<replaceable>guestport</replaceable></arg>
        </group></arg>
      <arg>--nat-pf<replaceable>N</replaceable>=delete=<replaceable>rule-name</replaceable></arg>
      <arg>--nat-tftp-prefix<replaceable>N</replaceable>=<replaceable>prefix</replaceable></arg>
      <arg>--nat-tftp-file<replaceable>N</replaceable>=<replaceable>filename</replaceable></arg>
      <arg>--nat-tftp-server<replaceable>N</replaceable>=<replaceable>IP-address</replaceable></arg>
      <arg>--nat-bind-ip<replaceable>N</replaceable>=<replaceable>IP-address</replaceable></arg>
      <arg>--nat-dns-pass-domain<replaceable>N</replaceable>=<group choice="plain">
          <arg choice="plain">on</arg>
          <arg choice="plain">off</arg>
        </group></arg>
      <arg>--nat-dns-proxy<replaceable>N</replaceable>=<group choice="plain">
          <arg choice="plain">on</arg>
          <arg choice="plain">off</arg>
        </group></arg>
      <arg>--nat-dns-host-resolver<replaceable>N</replaceable>=<group choice="plain">
          <arg choice="plain">on</arg>
          <arg choice="plain">off</arg>
        </group></arg>
      <arg>--nat-localhostreachable<replaceable>N</replaceable>=<group choice="plain">
          <arg choice="plain">on</arg>
          <arg choice="plain">off</arg>
        </group></arg>
      <arg>--nat-settings<replaceable>N</replaceable>=[<replaceable>mtu</replaceable>],[<replaceable>socksnd</replaceable>],[<replaceable>sockrcv</replaceable>],[<replaceable>tcpsnd</replaceable>],[<replaceable>tcprcv</replaceable>]</arg>
      <arg>--nat-alias-mode<replaceable>N</replaceable>=<group choice="plain">
          <arg choice="plain">default</arg>
          <arg choice="plain">[log],[proxyonly],[sameports]</arg>
        </group></arg>
    </cmdsynopsis>

    <cmdsynopsis id="synopsis-vboxmanage-modifyvm-other-hardware">
      <command>VBoxManage modifyvm</command>
      <group choice="req">
        <arg choice="plain"><replaceable>uuid</replaceable></arg>
        <arg choice="plain"><replaceable>vmname</replaceable></arg>
      </group>
      <arg>--mouse=<group choice="plain">
          <arg choice="plain">ps2</arg>
          <arg choice="plain">usb</arg>
          <arg choice="plain">usbtablet</arg>
          <arg choice="plain">usbmultitouch</arg>
          <arg choice="plain">usbmtscreenpluspad</arg>
        </group></arg>
      <arg>--keyboard=<group choice="plain">
          <arg choice="plain">ps2</arg>
          <arg choice="plain">usb</arg>
        </group></arg>
      <arg>--uart<replaceable>N</replaceable>=<group choice="plain">
          <arg choice="plain">off</arg>
          <arg choice="plain"><replaceable>IO-base</replaceable> <replaceable>IRQ</replaceable></arg>
        </group></arg>
      <arg>--uart-mode<replaceable>N</replaceable>=<group choice="plain">
          <arg choice="plain">disconnected</arg>
          <arg choice="plain">server <replaceable>pipe</replaceable></arg>
          <arg choice="plain">client <replaceable>pipe</replaceable></arg>
          <arg choice="plain">tcpserver <replaceable>port</replaceable></arg>
          <arg choice="plain">tcpclient <replaceable>hostname</replaceable>:<replaceable>port</replaceable></arg>
          <arg choice="plain">file <replaceable>filename</replaceable></arg>
          <arg choice="plain"><replaceable>device-name</replaceable></arg>
        </group></arg>
      <arg>--uart-type<replaceable>N</replaceable>=<group choice="plain">
          <arg choice="plain">16450</arg>
          <arg choice="plain">16550A</arg>
          <arg choice="plain">16750</arg>
        </group></arg>
      <arg>--lpt-mode<replaceable>N</replaceable>=<replaceable>device-name</replaceable></arg>
      <arg>--lpt<replaceable>N</replaceable>=<group choice="plain">
          <arg choice="plain">off</arg>
          <arg choice="plain"><replaceable>IO-base</replaceable> <replaceable>IRQ</replaceable></arg>
        </group></arg>
      <arg>--audio-controller=<group choice="plain">
          <arg choice="plain">ac97</arg>
          <arg choice="plain">hda</arg>
          <arg choice="plain">sb16</arg>
        </group></arg>
      <arg>--audio-codec=<group choice="plain">
          <arg choice="plain">stac9700</arg>
          <arg choice="plain">ad1980</arg>
          <arg choice="plain">stac9221</arg>
          <arg choice="plain">sb16</arg>
        </group></arg>
      <arg>--audio-driver=<group choice="plain">
          <arg choice="plain">none</arg>
          <arg choice="plain">default</arg>
          <arg choice="plain">null</arg>
          <arg choice="plain">dsound</arg>
          <arg choice="plain">was</arg>
          <arg choice="plain">oss</arg>
          <arg choice="plain">alsa</arg>
          <arg choice="plain">pulse</arg>
          <arg choice="plain">coreaudio</arg>
        </group></arg>
      <arg>--audio-enabled=<group choice="plain">
          <arg choice="plain">on</arg>
          <arg choice="plain">off</arg>
        </group></arg>
      <arg>--audio-in=<group choice="plain">
          <arg choice="plain">on</arg>
          <arg choice="plain">off</arg>
        </group></arg>
      <arg>--audio-out=<group choice="plain">
          <arg choice="plain">on</arg>
          <arg choice="plain">off</arg>
        </group></arg>
      <arg>--clipboard-mode=<group choice="plain">
          <arg choice="plain">disabled</arg>
          <arg choice="plain">hosttoguest</arg>
          <arg choice="plain">guesttohost</arg>
          <arg choice="plain">bidirectional</arg>
        </group></arg>
<!-- There is a currently undocumented option &#45;&#45;clipboard-file-transfers.
The implementation is not finished, so postpone documenting until it
actually is ready for users. -->
      <arg>--drag-and-drop=<group choice="plain">
          <arg choice="plain">disabled</arg>
          <arg choice="plain">hosttoguest</arg>
          <arg choice="plain">guesttohost</arg>
          <arg choice="plain">bidirectional</arg>
        </group></arg>
      <arg>--monitor-count=<replaceable>number</replaceable></arg>
      <arg>--usb-ehci=<group choice="plain">
          <arg choice="plain">on</arg>
          <arg choice="plain">off</arg>
        </group></arg>
      <arg>--usb-ohci=<group choice="plain">
          <arg choice="plain">on</arg>
          <arg choice="plain">off</arg>
        </group></arg>
      <arg>--usb-xhci=<group choice="plain">
          <arg choice="plain">on</arg>
          <arg choice="plain">off</arg>
        </group></arg>
      <arg>--usb-rename=<replaceable>old-name</replaceable> <replaceable>new-name</replaceable></arg>
    </cmdsynopsis>

    <cmdsynopsis id="synopsis-vboxmanage-modifyvm-recording">
      <command>VBoxManage modifyvm</command>
      <group choice="req">
        <arg choice="plain"><replaceable>uuid</replaceable></arg>
        <arg choice="plain"><replaceable>vmname</replaceable></arg>
      </group>
      <arg>--recording=<group choice="plain">
          <arg choice="plain">on</arg>
          <arg choice="plain">off</arg>
        </group></arg>
      <arg>--recording-screens=<group choice="plain">
          <arg choice="plain">all</arg>
          <arg choice="plain">none</arg>
          <arg choice="plain"><replaceable>screen-ID</replaceable>[,<replaceable>screen-ID</replaceable>...]</arg>
        </group></arg>
      <arg>--recording-file=<replaceable>filename</replaceable></arg>
      <arg>--recording-max-size=<replaceable>MB</replaceable></arg>
      <arg>--recording-max-time=<replaceable>msec</replaceable></arg>
      <arg>--recording-opts= <arg choice="plain"><replaceable>key</replaceable>=<replaceable>value</replaceable>[,<replaceable>key</replaceable>=<replaceable>value</replaceable>...]</arg></arg>
      <arg>--recording-video-fps=<replaceable>fps</replaceable></arg>
      <arg>--recording-video-rate=<replaceable>rate</replaceable></arg>
      <arg>--recording-video-res=<replaceable>width</replaceable> <replaceable>height</replaceable></arg>
    </cmdsynopsis>

    <cmdsynopsis id="synopsis-vboxmanage-modifyvm-vrde">
      <command>VBoxManage modifyvm</command>
      <group choice="req">
        <arg choice="plain"><replaceable>uuid</replaceable></arg>
        <arg choice="plain"><replaceable>vmname</replaceable></arg>
      </group>
      <arg>--vrde=<group choice="plain">
          <arg choice="plain">on</arg>
          <arg choice="plain">off</arg>
        </group></arg>
      <arg>--vrde-property=<replaceable>property-name</replaceable>= <arg><replaceable>property-value</replaceable></arg></arg>
      <arg>--vrde-extpack=<group choice="plain">
          <arg choice="plain">default</arg>
          <arg choice="plain"><replaceable>name</replaceable></arg>
        </group></arg>
      <arg>--vrde-port=<replaceable>port</replaceable></arg>
      <arg>--vrde-address=<replaceable>hostip</replaceable></arg>
      <arg>--vrde-auth-type=<group choice="plain">
          <arg choice="plain">null</arg>
          <arg choice="plain">external</arg>
          <arg choice="plain">guest</arg>
        </group></arg>
      <arg>--vrde-auth-library=<group choice="plain">
          <arg choice="plain">default</arg>
          <arg choice="plain"><replaceable>name</replaceable></arg>
        </group></arg>
      <arg>--vrde-multi-con=<group choice="plain">
          <arg choice="plain">on</arg>
          <arg choice="plain">off</arg>
        </group></arg>
      <arg>--vrde-reuse-con=<group choice="plain">
          <arg choice="plain">on</arg>
          <arg choice="plain">off</arg>
        </group></arg>
      <arg>--vrde-video-channel=<group choice="plain">
          <arg choice="plain">on</arg>
          <arg choice="plain">off</arg>
        </group></arg>
      <arg>--vrde-video-channel-quality=<replaceable>percent</replaceable></arg>
    </cmdsynopsis>

    <cmdsynopsis id="synopsis-vboxmanage-modifyvm-teleport">
      <command>VBoxManage modifyvm</command>
      <group choice="req">
        <arg choice="plain"><replaceable>uuid</replaceable></arg>
        <arg choice="plain"><replaceable>vmname</replaceable></arg>
      </group>
      <arg>--teleporter=<group choice="plain">
          <arg choice="plain">on</arg>
          <arg choice="plain">off</arg>
        </group></arg>
      <arg>--teleporter-port=<replaceable>port</replaceable></arg>
      <arg>--teleporter-address=<group choice="plain">
          <arg choice="plain"><replaceable>address</replaceable></arg>
          <arg choice="plain">empty</arg>
        </group></arg>
      <arg>--teleporter-password=<replaceable>password</replaceable></arg>
      <arg>--teleporter-password-file=<group choice="plain">
          <arg choice="plain"><replaceable>filename</replaceable></arg>
          <arg choice="plain">stdin</arg>
        </group></arg>
      <arg>--cpuid-portability-level=<replaceable>level</replaceable></arg>
      <arg>--cpuid-set=<replaceable>leaf</replaceable><arg>:<replaceable>subleaf</replaceable></arg> <replaceable>eax</replaceable>&nbsp;<replaceable>ebx</replaceable>&nbsp;<replaceable>ecx</replaceable>&nbsp;<replaceable>edx</replaceable></arg>
      <arg>--cpuid-remove=<replaceable>leaf</replaceable><arg>:<replaceable>subleaf</replaceable></arg></arg>
      <arg>--cpuid-remove-all</arg>
    </cmdsynopsis>

    <cmdsynopsis id="synopsis-vboxmanage-modifyvm-debugging">
      <command>VBoxManage modifyvm</command>
      <group choice="req">
        <arg choice="plain"><replaceable>uuid</replaceable></arg>
        <arg choice="plain"><replaceable>vmname</replaceable></arg>
      </group>
      <arg>--tracing-enabled=<group choice="plain">
          <arg choice="plain">on</arg>
          <arg choice="plain">off</arg>
        </group></arg>
      <arg>--tracing-config=<replaceable>string</replaceable></arg>
      <arg>--tracing-allow-vm-access=<group choice="plain">
          <arg choice="plain">on</arg>
          <arg choice="plain">off</arg>
        </group></arg>
    </cmdsynopsis>

    <cmdsynopsis id="synopsis-vboxmanage-modifyvm-usbcardreader">
      <command>VBoxManage modifyvm</command>
      <group choice="req">
        <arg choice="plain"><replaceable>uuid</replaceable></arg>
        <arg choice="plain"><replaceable>vmname</replaceable></arg>
      </group>
      <arg>--usb-card-reader=<group choice="plain">
          <arg choice="plain">on</arg>
          <arg choice="plain">off</arg>
        </group></arg>
    </cmdsynopsis>

    <cmdsynopsis id="synopsis-vboxmanage-modifyvm-autostart">
      <command>VBoxManage modifyvm</command>
      <group choice="req">
        <arg choice="plain"><replaceable>uuid</replaceable></arg>
        <arg choice="plain"><replaceable>vmname</replaceable></arg>
      </group>
      <arg>--autostart-enabled=<group choice="plain">
          <arg choice="plain">on</arg>
          <arg choice="plain">off</arg>
        </group></arg>
      <arg>--autostart-delay=<replaceable>seconds</replaceable></arg>
<!-- There is a currently undocumented option &#45;&#45;autostop-type.
Most autostart service implementations either ignore it or rely it is
left unchanged due to otherwise running into timeouts established by the
host OS, defeating the purpose. Not worth spending time on documenting
it unless this changes. -->
    </cmdsynopsis>

    <cmdsynopsis id="synopsis-vboxmanage-modifyvm-guest-debug">
      <command>VBoxManage modifyvm</command>
      <group choice="req">
        <arg choice="plain"><replaceable>uuid</replaceable></arg>
        <arg choice="plain"><replaceable>vmname</replaceable></arg>
      </group>
      <arg>--guest-debug-provider=<group choice="plain">
          <arg choice="plain">none</arg>
          <arg choice="plain">native</arg>
          <arg choice="plain">gdb</arg>
          <arg choice="plain">kd</arg>
        </group></arg>
      <arg>--guest-debug-io-provider=<group choice="plain">
          <arg choice="plain">none</arg>
          <arg choice="plain">tcp</arg>
          <arg choice="plain">udp</arg>
          <arg choice="plain">ipc</arg>
        </group></arg>
      <arg>--guest-debug-address=<group choice="plain">
          <arg choice="plain"><replaceable>IP-Address</replaceable></arg>
          <arg choice="plain"><replaceable>path</replaceable></arg>
        </group></arg>
      <arg>--guest-debug-port=<replaceable>port</replaceable></arg>
    </cmdsynopsis>

    <cmdsynopsis id="synopsis-vboxmanage-modifyvm-pcipassthrough">
      <command>VBoxManage modifyvm</command>
      <group choice="req">
        <arg choice="plain"><replaceable>uuid</replaceable></arg>
        <arg choice="plain"><replaceable>vmname</replaceable></arg>
      </group>
      <arg>--pci-attach=<replaceable>host-PCI-address</replaceable><arg>@<replaceable>guest-PCI-bus-address</replaceable></arg></arg>
      <arg>--pci-detach=<replaceable>host-PCI-address</replaceable></arg>
    </cmdsynopsis>

    <cmdsynopsis id="synopsis-vboxmanage-modifyvm-testing">
      <command>VBoxManage modifyvm</command>
      <group choice="req">
        <arg choice="plain"><replaceable>uuid</replaceable></arg>
        <arg choice="plain"><replaceable>vmname</replaceable></arg>
      </group>
      <arg>--testing-enabled=<group choice="plain"><arg choice="plain">on</arg><arg choice="plain">off</arg></group></arg>
      <arg>--testing-mmio=<group choice="plain"><arg choice="plain">on</arg><arg choice="plain">off</arg></group></arg>
      <arg>--testing-cfg-dword<replaceable>idx</replaceable>=<replaceable>value</replaceable></arg>
    </cmdsynopsis>
  </refsynopsisdiv>

  <refsect1>
    <title>Description</title>
    <para>
      The <command>VBoxManage modifyvm</command> command enables you to
      change the properties of a registered virtual machine (VM) that is
      not running.
    </para>
    <para>
      Most of these properties correspond to the VM settings that are
      shown in each VM's <emphasis role="bold">Settings</emphasis>
      dialog in the VirtualBox Manager. See
      <xref linkend="BasicConcepts" />. However, some settings can only
      be viewed and managed with the <command>VBoxManage</command>
      command.
    </para>
    <para>
      You can use the <command>VBoxManage modifyvm</command> command to
      change VM settings only when the VM is powered off. The VM cannot
      be running or in saved state when you use this command.
    </para>
    <para>
      You can use the <command>VBoxManage controlvm</command> command to
      dynamically change some VM machine settings while the VM is
      running. See <xref linkend="vboxmanage-controlvm" />.
    </para>
    <refsect2 id="vboxmanage-modifyvm-general">
      <title>General Settings</title>
      <remark role="help-copy-synopsis"/>
      <para>
        The following options enable you to modify general information
        about your VM.
      </para>
      <para>
        The <command>VBoxManage modifyvm</command> command supports the
        following options:
      </para>
      <variablelist>
        <varlistentry>
          <term><option>--name=<replaceable>vmname</replaceable></option></term>
          <listitem><para>
              Changes the name of the VM and its related internal VM
              files. See <xref linkend="vboxmanage-createvm"/>.
            </para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--groups=<replaceable>group</replaceable></option></term>
          <listitem><para>
              Changes the group membership of a VM. Group names always
              begin with a slash character (<literal>/</literal>) and
              can be nested. By default, VMs are members of the
              <literal>/</literal> group. A VM can be member of multiple
              groups, but its primary group determines the directory
              structure where the internal VM files are placed by default.
            </para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--description=<replaceable>desc</replaceable></option></term>
          <listitem><para>
              Changes the optional VM description. Use a description to
              record details about the VM in a meaningful way. The GUI
              interprets HTML markup while the <command>VBoxManage
              modifyvm</command> command enables you include arbitrary
              strings that can contain multiple lines.
            </para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--os-type=<replaceable>OS-type</replaceable></option></term>
          <listitem><para>
              Specifies the guest operating system (OS) information for
              the VM. Use the <command>VBoxManage list ostypes</command>
              command to view the OS type identifiers.
            </para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--icon-file=<replaceable>filename</replaceable></option></term>
          <listitem><para>
              Specifies the path to the VM icon file in PNG format
              on the host system. The icon is shown in the VM manager
              UI and when running the VM with UI.
            </para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--memory=<replaceable>size</replaceable></option></term>
          <listitem><para>
              Specifies the amount of host system RAM to allocate to the
              VM. The size is in MB. See
              <xref linkend="create-vm-wizard" />.
            </para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--page-fusion=on | off</option></term>
          <listitem><para>
              Enables or disables the Page Fusion feature, which is
              disabled by default. Use the Page Fusion feature to
              minimize the memory duplication between VMs that have
              similar configurations and that run on the same host
              system. See <xref linkend="guestadd-pagefusion" />.
            </para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--vram=<replaceable>size</replaceable></option></term>
          <listitem><para>
              Specifies the amount of RAM to allocate to the virtual
              graphics card. See <xref linkend="settings-display" />.
            </para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--acpi=on | off</option></term>
          <listitem><para>
              Determines whether the VM has ACPI support. See
              <xref linkend="settings-motherboard" />.
            </para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--ioapic=on | off</option></term>
          <listitem><para>
              Determines whether the VM has I/O APIC support. See
              <xref linkend="settings-motherboard" />.
            </para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--hardware-uuid=<replaceable>uuid</replaceable></option></term>
          <listitem><para>
              Specifies the Universally Unique Identifier (UUID) to
              present to the guest VM in memory tables (DMI/SMBIOS),
              hardware, and VM properties. By default this hardware UUID
              is the same as the VM UUID. Cloning a VM and the teleporting
              feature automatically preserve the hardware UUID value.
              Likewise for Virtual Appliance export and import, but only
              if both operations are done by &product-name;.
            </para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--cpus=<replaceable>CPU-count</replaceable></option></term>
          <listitem><para>
              Specifies the number of virtual CPUs to assign to the VM.
              See <xref linkend="settings-processor" />.
            </para><para>
              If CPU hot-plugging is enabled, this option specifies the
              maximum number of virtual CPUs that can be plugged into
              the VMs.
            </para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--cpu-hotplug=on | off</option></term>
          <listitem><para>
              Enables or disables CPU hot-plugging. When enabled, you
              can dynamically add virtual CPUs to a VM or remove virtual
              CPUs from a VM. See <xref linkend="cpuhotplug" />.
            </para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--plug-cpu=<replaceable>CPU-ID</replaceable></option></term>
          <listitem><para>
              Adds a virtual CPU to the VM.
              <replaceable>CPU-ID</replaceable> is the index of the
              virtual CPU to add. A valid index value is a number from
              <literal>0</literal> to the maximum number of CPUs that
              you configured by using the <option>--cpus</option>
              option.
            </para><para>
              Only use this option if CPU hot-plugging is enabled.
            </para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--unplug-cpu=<replaceable>CPU-ID</replaceable></option></term>
          <listitem><para>
              Removes a virtual CPU from the VM.
              <replaceable>CPU-ID</replaceable> is the index of the
              virtual CPU to remove. A valid index value is a number
              from <literal>1</literal> to the maximum number of CPUs
              that you configured by using the <option>--cpus</option>
              option.
            </para><para>
              Only use this option if CPU hot-plugging is enabled.
            </para><para>
              Note that you cannot remove CPU 0.
            </para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--cpuexectioncap=<replaceable>percentage</replaceable></option></term>
          <listitem>
            <para>
              Specifies how much CPU time a virtual CPU can use. A valid
              value is from <literal>1</literal> to
              <literal>100</literal>. A value of 50 indicates that a
              single virtual CPU can use up to 50% of a single host CPU.
            </para>
            <para>
              Use this feature with caution, it can have unexpected results
              including timekeeping problems and lower performance than
              specified. If you want to limit the resource usage of a VM
              it is more reliable to pick an appropriate number of VCPUs.
            </para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--pae=on | off</option></term>
          <listitem><para>
              Enables or disables physical address extension (PAE). See
              <xref linkend="settings-processor" />.
            </para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--long-mode=on | off</option></term>
          <listitem><para>
              Enables or disables long mode. See
              <xref linkend="settings-processor" />.
            </para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--ibpb-on-vm-exit=on | off</option></term>
          <listitem><para>
              Enables use of Indirect Branch Prediction Barrier (IBPB)
              on every VM exit.
            </para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--ibpb-on-vm-entry=on | off</option></term>
          <listitem><para>
              Enables use of Indirect Branch Prediction Barrier (IBPB)
              on every VM entry.
            </para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--spec-ctrl=on | off</option></term>
          <listitem><para>
              Enables or disables the exposure of speculation control
              interfaces to the guest VM. These interfaces must be
              available on the host system.
            </para><para>
              Depending on the host CPU and the workload, enabling
              speculation control might significantly reduce
              performance.
            </para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--l1d-flush-on-sched=on | off</option></term>
          <listitem><para>
              Enables or disables level 1 data cache flushing when a
              thread is scheduled to execute guest code. See
              <xref linkend="sec-rec-cve-2018-3646" />.
            </para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--l1d-flush-on-vm-entry=on | off</option></term>
          <listitem><para>
              Enables or disables level 1 data cache flushing on every
              VM entry. See <xref linkend="sec-rec-cve-2018-3646" />.
            </para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--mds-clear-on-sched=on | off</option></term>
          <listitem><para>
              Enables CPU buffer clearing when a thread is scheduled to
              execute guest code. See
              <xref linkend="sec-rec-cve-2018-12126-et-al" />.
            </para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--mds-clear-on-vm-entry=on | off</option></term>
          <listitem><para>
              Enables CPU buffer clearing on every VM entry. See
              <xref linkend="sec-rec-cve-2018-12126-et-al" />.
            </para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--cpu-profile=host | Intel 8086 | Intel 80286 | Intel 80386</option></term>
          <listitem><para>
              Specifies the profile to use for guest CPU emulation.
              Specify a value that is based on the host system CPU
              (<literal>host</literal>) or one of the following older
              Intel micro-architectures: <literal>8086</literal>,
              <literal>80286</literal>, or <literal>80386</literal>.
            </para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--hpet=on | off</option></term>
          <listitem><para>
              Enables or disables a High Precision Event Timer (HPET)
              that can replace a legacy system timer. This feature is
              disabled by default. Note HPET is supported on Windows
              versions starting with Vista.
            </para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--hwvirtex=on | off</option></term>
          <listitem><para>
              Enables or disables the use of hardware virtualization
              extensions in the processor of the host system. Such
              extensions are Intel VT-x or AMD-V. See
              <xref linkend="hwvirt" />.
            </para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--triple-fault-reset=on | off</option></term>
          <listitem><para>
              Enables or disables the resetting of the guest VM instead
              of triggering a Guru Meditation. Some guest VMs raise a
              triple fault to reset the CPU, so sometimes resetting the
              guest VM is the best outcome. This option only applies to
              guests that do not use symmetric multiprocessing (SMP).
            </para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--apic=on | off</option></term>
          <listitem><para>
              Enables or disables APIC. With APIC, OSes can use
              more than 16 interrupt requests (IRQs) to avoid IRQ
              sharing and to improve reliability. APIC is enabled by
              default. See <xref linkend="settings-motherboard" />.
            </para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--x2apic=on | off</option></term>
          <listitem><para>
              Enables or disables the CPU x2APIC feature. CPU x2APIC
              enables an OS to run more efficiently on high core count
              configurations and to optimize interrupt distribution in
              virtualized environments. This feature is enabled by
              default.
            </para><para>
              Disable this feature when the OS that runs on a host
              system or a guest VM is incompatible with CPU x2APIC.
            </para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--paravirt-provider=none | default | legacy | minimal | hyperv | kvm</option></term>
          <listitem><para>
              Specifies one of the following paravirtualization
              interfaces to provide to the guest OS:
            </para><itemizedlist>
              <listitem><para>
                  <literal>none</literal> does not expose any
                  paravirtualization interface.
                </para></listitem>
              <listitem><para>
                  <literal>default</literal> selects the appropriate
                  interface based on the guest OS type when starting the
                  VM. This is the default value used when creating new
                  VMs.
                </para></listitem>
              <listitem><para>
                  <literal>legacy</literal> selects a paravirtual
                  interface for VMs that were created by older
                  &product-name; versions.
                </para></listitem>
              <listitem><para>
                  <literal>minimal</literal> is required for Mac OS X
                  guest VMs.
                </para></listitem>
              <listitem><para>
                  <literal>kvm</literal> is recommended for Linux guest
                  VMs. See <xref linkend="gimproviders" />.
                </para></listitem>
              <listitem><para>
                  <literal>hyperv</literal> is recommended for Windows
                  guest VMs. See <xref linkend="gimproviders" />.
                </para></listitem>
            </itemizedlist></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--paravirt-debug=<replaceable>property</replaceable>=<replaceable>value</replaceable></option></term>
          <listitem><para>
              Specifies debugging properties that are specific to the
              paravirtualization provider configured for the specified
              VM. See <xref linkend="gimdebug" />.
            </para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--nested-paging=on | off</option></term>
          <listitem><para>
              Enables or disables the nested paging feature in the
              processor of the host system. This option is available
              only when hardware virtualization is enabled. See
              <xref linkend="hwvirt" /> and
              <xref linkend="sec-rec-cve-2018-3646" />.
            </para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--large-pages=on | off</option></term>
          <listitem><para>
              Enables or disables the hypervisor's use of large pages,
              which can improve performance by up to 5%. The use of
              large pages reduces TLB use and overhead. This option is
              available only when both hardware virtualization and
              nested paging are enabled.
            </para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--vtx-vpid=on | off</option></term>
          <listitem><para>
              Enables or disables the use of the tagged TLB (VPID)
              feature in the processor of your host system. See
              <xref linkend="hwvirt" />. This option is available only
              when hardware virtualization is enabled on Intel VT-x.
            </para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--vtx-ux=on | off</option></term>
          <listitem><para>
              Enables or disables the use of unrestricted guest mode for
              executing the guest VM. This option is available only when
              hardware virtualization is enabled on Intel VT-x.
            </para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--nested-hw-virt=on | off</option></term>
          <listitem><para>
              Enables or disables nested virtualization. Enabling makes
              hardware virtualization features available to the VM. See
              <xref linkend="nested-virt" />.
            </para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--virt-vmsave-vmload=on | off</option></term>
          <listitem><para>
              If hardware virtualization is enabled and the host has an
              AMD CPU, this setting enables or disables the use of the
              virtualized vmsave/vmload host feature while executing the
              VM. It is enabled by default. It is recommended to leave it
              enabled as it has a drastic impact on performance while
              executing nested VMs when using the nested hardware
              virtualization feature.
              <xref linkend="nested-virt" />.
            </para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--accelerate-3d=on | off</option></term>
          <listitem><para>
              Enables or disables hardware 3D acceleration for the
              graphics adapter variants which support it. This option
              has an effect only when the Guest Additions are installed.
              See <xref linkend="guestadd-3d" />.
            </para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--accelerate-2d-video=on | off</option></term>
          <listitem><para>
              Enables or disables 2D video acceleration for the graphics
              adapter variants which support it. This option has an effect
              only when the Guest Additions are installed. See
              <xref linkend="guestadd-2d" />.
            </para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--chipset=piix3 | ich9</option></term>
          <listitem><para>
              Specify the Intel chipset for &product-name; to emulate.
              The default value is the Intel PIIX3 chipset
              (<literal>piix3</literal>).
            </para><para>
              Change this value only if you need to relax some of the
              chipset constraints. See
              <xref linkend="settings-motherboard" />.
            </para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--iommu=none | automatic | amd | intel</option></term>
          <listitem><para>
              Specifies the IOMMU type for &product-name; to emulate.
              Both Intel and AMD IOMMU emulation currently require the
              use of the Intel ICH9 chipset (see
              <option>--chipset</option> option).
            </para><para>
              Valid values are as follows:
            </para><itemizedlist>
              <listitem><para>
                  <literal>none</literal> &ndash; No IOMMU is present
                  and is the default value.
                </para></listitem>
              <listitem><para>
                  <literal>automatic</literal> &ndash; An IOMMU is
                  present but its type is automatically chosen to match
                  the host CPU vendor when the VM is powered on.
                </para></listitem>
              <listitem><para>
                  <literal>amd</literal> &ndash; An AMD IOMMU is
                  present.
                </para></listitem>
              <listitem><para>
                  <literal>intel</literal> &ndash; An Intel IOMMU is
                  present.
                </para></listitem>
            </itemizedlist></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--tpm-type=none | 1.2 | 2.0 | host | swtpm</option></term>
          <listitem><para>
              Specifies the TPM type for &product-name; to emulate.
            </para><para>
              Valid values are as follows:
            </para><itemizedlist>
              <listitem><para>
                  <literal>none</literal> &ndash; No TPM is present
                  and is the default value.
                </para></listitem>
              <listitem><para>
                  <literal>1.2</literal> &ndash; A TPM conforming to the TCG specification
                  version 1.2 is present.
                </para></listitem>
              <listitem><para>
                  <literal>2.0</literal> &ndash; A TPM conforming to the TCG specification
                  version 2.0 is present.
                </para></listitem>
              <listitem><para>
                  <literal>host</literal> &ndash; The host TPM is passed through to the guest.
                  May not be available on all supported host platforms.
                </para></listitem>
              <listitem><para>
                  <literal>swtpm</literal> &ndash; The VM connects to an external TPM emulation
                  compliant to swtpm. Requires to set the TPM location to connect to (see
                  <option>--tpm-location</option> option).
                </para></listitem>
            </itemizedlist></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--bios-logo-fade-in=on | off</option></term>
          <listitem><para>
              Specifies whether the BIOS logo fades in on VM startup. By
              default, an &product-name; logo is shown.
            </para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--bios-logo-fade-out=on | off</option></term>
          <listitem><para>
              Specifies whether the BIOS logo fades out on VM startup.
            </para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--bios-logo-display-time=<replaceable>msec</replaceable></option></term>
          <listitem><para>
              Specifies the amount of time in milliseconds that the BIOS
              logo is visible.
            </para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--bios-logo-image-path=<replaceable>pathname</replaceable></option></term>
          <listitem><para>
              Replaces the existing BIOS logo with a different image.
              The replacement image must be an uncompressed 16, 256 or 16M
              color bitmap file (BMP) that does not contain color space
              information (Windows 3.0 format). Also ensure that the
              image is no larger than 640 X 480 pixels.
            </para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--bios-boot-menu=disabled | menuonly | messageandmenu</option></term>
          <listitem><para>
              Specifies whether the BIOS permits you to select a
              temporary boot device. Valid values are:
            </para><itemizedlist>
              <listitem><para>
                  <literal>disabled</literal> outputs the alternate boot
                  device message and permits you to select a temporary
                  boot device by pressing F12.
                </para></listitem>
              <listitem><para>
                  <literal>menuonly</literal> suppresses the alternate
                  boot device message, but permits you to select a
                  temporary boot device by pressing F12.
                </para></listitem>
              <listitem><para>
                  <literal>messageandmenu</literal> suppresses the
                  alternate boot device message and prevents you from
                  selecting a temporary boot device by pressing F12.
                </para></listitem>
            </itemizedlist></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--bios-apic=x2apic | apic | disabled</option></term>
          <listitem><para>
              Specifies the APIC level of the firmware. Valid values
              are: <literal>x2apic</literal>, <literal>apic</literal>,
              and <literal>disabled</literal>. When the value is
              <literal>disabled</literal>, neither the
              <literal>apic</literal> nor the <literal>x2apic</literal>
              version of the firmware is used.
            </para><para>
              Note that if you specify the <literal>x2apic</literal>
              value and x2APIC is unsupported by the virtual CPU, the
              APIC level downgrades to <literal>apic</literal>, if
              supported. Otherwise, the APIC level downgrades to
              <literal>disabled</literal>. Similarly, if you specify the
              <literal>apic</literal> value and APIC is unsupported by
              the virtual CPU, the APIC level downgrades to
              <literal>disabled</literal>.
            </para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--bios-system-time-offset=<replaceable>msec</replaceable></option></term>
          <listitem><para>
              Specifies the time offset in milliseconds of the guest VM
              relative to the time on the host system. If the offset
              value is positive, the guest VM time runs ahead of the
              time on the host system.
            </para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--bios-pxe-debug=on | off</option></term>
          <listitem><para>
              Enables or disables additional debugging output when using
              the Intel PXE boot ROM. The debug output is written to the
              release log file. See
              <xref linkend="collect-debug-info" />.
            </para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--system-uuid-le=on | off</option></term>
          <listitem><para>
              Enables or disables representing the system UUID in little
              endian form. The default value is <literal>on</literal> for
              new VMs. For old VMs the setting is <literal>off</literal> to
              keep the content of the DMI/SMBIOS table unchanged, which can
              be important for Windows license activation.
            </para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--boot<replaceable>N</replaceable>=none | floppy | dvd | disk | net</option></term>
          <listitem><para>
              Enables you to specify the boot device order for the VM by
              assigning one of the device types to each of the four boot
              device slots that are represented by
              <replaceable>N</replaceable> in the option name.
            </para><para>
              A value of 1 for <replaceable>N</replaceable> represents
              the first boot device slot, and so on.
            </para><para>
              The device types are <literal>floppy</literal> for floppy
              disks, <literal>dvd</literal> for DVDs or CDs,
              <literal>disk</literal> for hard disks, and
              <literal>net</literal> for a network device. A value of
              <literal>none</literal> indicates that no boot device is
              associated with the specified slot.
            </para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--rtc-use-utc=on | off</option></term>
          <listitem><para>
              Specifies whether the real-time clock (RTC) uses
              coordinated universal time (UTC). See
              <xref linkend="settings-motherboard" />.
            </para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--graphicscontroller=none | vboxvga | vmsvga | vboxsvga</option></term>
          <listitem><para>
              Specifies the graphics controller type to use. See
              <xref linkend="settings-screen" />.
            </para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--snapshot-folder=default | <replaceable>pathname</replaceable></option></term>
          <listitem><para>
              Specifies the name of the VM's snapshot storage folder. If
              you specify <literal>default</literal>, the folder name is
              <filename>Snapshots/</filename> in the machine folder.
            </para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--firmware=bios | efi | efi32 | efi64</option></term>
          <listitem><para>
              Specifies the firmware used to boot the VM. Valid values
              are: <literal>bios</literal>, <literal>efi</literal>,
              <literal>efi32</literal>, or <literal>efi64</literal>. Use
              EFI values with care.
            </para><para>
              By default, BIOS firmware is used.
            </para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--guest-memory-balloon=<replaceable>size</replaceable></option></term>
          <listitem><para>
              Specifies the size of the guest memory balloon. The guest
              memory balloon is the memory allocated by the Guest
              Additions from the guest OS and returned to the hypervisor
              for use by other VMs. Specify
              <replaceable>size</replaceable> in megabytes. The default
              value is <literal>0</literal> megabytes. See
              <xref linkend="guestadd-balloon" />.
            </para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--default-frontend=default | <replaceable>name</replaceable></option></term>
          <listitem><para>
              Specifies the default frontend to use when starting the
              specified VM. If you specify <literal>default</literal>,
              the VM is shown in a window on the user's desktop. See
              <xref linkend="vboxmanage-startvm" />.
            </para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--vm-process-priority=default | flat | low | normal | high</option></term>
          <listitem><para>
              Specifies the priority scheme of the VM process to use
              when starting the specified VM and while the VM runs.
            </para><para>
              The following valid values are:
            </para><itemizedlist>
              <listitem><para>
                  <literal>default</literal> &ndash; Default process
                  priority determined by the OS.
                </para></listitem>
              <listitem><para>
                  <literal>flat</literal> &ndash; Assumes a scheduling
                  policy which puts the process at the default priority
                  and with all threads at the same priority.
                </para></listitem>
              <listitem><para>
                  <literal>low</literal> &ndash;  Assumes a scheduling
                  policy which puts the process mostly below the default
                  priority of the host OS.
                </para></listitem>
              <listitem><para>
                  <literal>normal</literal> &ndash; Assume a scheduling
                  policy which shares the CPU resources fairly with
                  other processes running with the default priority of
                  the host OS.
                </para></listitem>
              <listitem><para>
                  <literal>high</literal> &ndash; Assumes a scheduling
                  policy which puts the task above the default priority of
                  the host OS. This policy might easily cause other tasks
                  in the system to starve.
                </para></listitem>
            </itemizedlist></listitem>
        </varlistentry>
      </variablelist>
    </refsect2>
    <refsect2 id="vboxmanage-modifyvm-networking">
      <title>Networking Settings</title>
      <remark role="help-copy-synopsis"/>
      <para>
        The following options enable you to modify networking on your
        VM. With all these options, <replaceable>N</replaceable> is an
        integer greater than zero that represents the particular virtual
        network adapter to configure.
      </para>
      <variablelist>
        <varlistentry>
          <term><option>--nic<replaceable>N</replaceable>=none | null | nat | natnetwork | bridged | intnet | hostonly | generic</option></term>
          <listitem><para>
              Configures the network type used by each virtual network
              card in the VM.
            </para><para>
              The following valid values correspond to the modes
              described in <xref linkend="networkingmodes" />:
            </para><itemizedlist>
              <listitem><para>
                  <literal>none</literal> &ndash; No networking present
                </para></listitem>
              <listitem><para>
                  <literal>null</literal> &ndash; Not connected to the
                  host system
                </para></listitem>
              <listitem><para>
                  <literal>nat</literal> &ndash; Use network address
                  translation (NAT)
                </para></listitem>
              <listitem><para>
                  <literal>natnetwork</literal> &ndash; Use a NAT
                  network
                </para></listitem>
              <listitem><para>
                  <literal>bridged</literal> &ndash; Use bridged
                  networking
                </para></listitem>
              <listitem><para>
                  <literal>intnet</literal> &ndash; Use internal
                  networking
                </para></listitem>
              <listitem><para>
                  <literal>hostonly</literal> &ndash; Use host-only
                  networking
                </para></listitem>
              <listitem><para>
                  <literal>generic</literal> &ndash; Access rarely used
                  sub-modes
                </para></listitem>
            </itemizedlist></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--nic-type<replaceable>N</replaceable>=Am79C970A | Am79C973 | 82540EM | 82543GC | 82545EM | virtio</option></term>
          <listitem><para>
              Identifies the type of networking hardware that
              &product-name; presents to the guest VM for the specified
              virtual network card. See <xref linkend="nichardware" />.
            </para><para>
              Valid values are as follows:
            </para><itemizedlist>
              <listitem><para>
                  <literal>Am79C970A</literal> represents the AMD PCNet
                  PCI II.
                </para></listitem>
              <listitem><para>
                  <literal>Am79C973</literal> represents the AMD PCNet
                  FAST III, which is the default value.
                </para></listitem>
              <listitem><para>
                  <literal>82540EM</literal> represents the Intel
                  PRO/1000 MT Desktop.
                </para></listitem>
              <listitem><para>
                  <literal>82543GC</literal> represents the Intel
                  PRO/1000 T Server.
                </para></listitem>
              <listitem><para>
                  <literal>82545EM</literal> represents the Intel
                  PRO/1000 MT Server.
                </para></listitem>
              <listitem><para>
                  <literal>virtio</literal> represents a paravirtualized
                  network adapter.
                </para></listitem>
            </itemizedlist></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--cable-connected<replaceable>N</replaceable>=on | off</option></term>
          <listitem><para>
              Temporarily disconnects a virtual network interface, as if
              you pull a network cable from a physical network card. You
              might use this option to reset certain software components
              in the VM.
            </para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--nic-trace<replaceable>N</replaceable>=on | off</option></term>
          <listitem><para>
              Enables or disables network tracing for the specified
              virtual network card.
            </para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--nic-trace-file<replaceable>N</replaceable>=<replaceable>filename</replaceable></option></term>
          <listitem><para>
              Specifies the absolute path of the file in which to write
              trace log information. Use this option if network tracing
              is enabled.
            </para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--nic-property<replaceable>N</replaceable>=<replaceable>name</replaceable>=<replaceable>value</replaceable></option></term>
          <listitem><para>
              Enables you to set property values and pass them to rarely
              used network backends. To use this option, you must also
              use the <option>--nic-generic-drv</option> option.
            </para><para>
              These properties are specific to the backend engine and
              differ between the UDP Tunnel and the VDE backend drivers.
              For property examples, see
              <xref linkend="network_udp_tunnel" />.
            </para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--nic-speed<replaceable>N</replaceable>=<replaceable>kbps</replaceable></option></term>
          <listitem><para>
              Specifies the throughput rate in kilobits per second for
              rarely used networking sub-modes such as VDE network and
              UDP Tunnel. Use this option only if you used the
              <option>--nic</option> option to enable generic networking
              for the specified virtual network card.
            </para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--nic-boot-prio<replaceable>N</replaceable>=<replaceable>priority</replaceable></option></term>
          <listitem><para>
              Assigns a priority to each NIC that determines the order
              in which that NIC is used to perform a PXE network boot.
              The priority value is an integer in the range from
              <literal>0</literal> to <literal>4</literal>. Priority
              <literal>0</literal>, which is the default value, is the
              lowest priority. Priority <literal>1</literal> is the
              highest priority, and priorities <literal>3</literal> and
              <literal>4</literal> are lower.
            </para><para>
              This option has an effect only when using the Intel PXE
              boot ROM.
            </para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--nic-promisc<replaceable>N</replaceable>=deny | allow-vms | allow-all</option></term>
          <listitem><para>
              Enables you to specify whether to deny or allow
              promiscuous mode for the specified VM virtual network
              card. This option is relevant only for bridged networking.
              Valid values are as follows:
            </para><itemizedlist>
              <listitem><para>
                  <literal>deny</literal> hides any traffic that is not
                  intended for the VM. This is the default value.
                </para></listitem>
              <listitem><para>
                  <literal>allow-vms</literal> hides all host traffic
                  from the VM, but allows the VM to see traffic to and
                  from other VMs.
                </para></listitem>
              <listitem><para>
                  <literal>allow-all</literal> allows the VM to see all
                  traffic.
                </para></listitem>
            </itemizedlist></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--nic-bandwidth-group<replaceable>N</replaceable>=none | <replaceable>name</replaceable></option></term>
          <listitem><para>
              Adds or removes a bandwidth group assignment to the
              specified virtual network interface. Valid values are as
              follows:
            </para><itemizedlist>
              <listitem><para>
                  <literal>none</literal> removes any current bandwidth
                  group assignment from the specified virtual network
                  interface.
                </para></listitem>
              <listitem><para>
                  <replaceable>name</replaceable> adds a bandwidth group
                  assignment to the specified virtual network interface.
                </para></listitem>
            </itemizedlist><para>
              See <xref linkend="network_bandwidth_limit" />.
            </para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--bridge-adapter<replaceable>N</replaceable>=none | <replaceable>device-name</replaceable></option></term>
          <listitem><para>
              Specifies the host interface to use for the specified
              virtual network interface. See
              <xref linkend="network_bridged" />. Use this option only
              if you used the <option>--nic</option> option to enable
              bridged networking for the specified virtual network card.
            </para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--host-only-adapter<replaceable>N</replaceable>=none | <replaceable>device-name</replaceable></option></term>
          <listitem><para>
              Specifies which host-only networking interface to use for
              the specified virtual network interface. See
              <xref linkend="network_hostonly" />. Use this option only
              if you used the <option>--nic</option> option to enable
              host-only networking for the specified virtual network
              card.
            </para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--intnet<replaceable>N</replaceable>=<replaceable>network-name</replaceable></option></term>
          <listitem><para>
              Specifies the name of the internal network. See
              <xref linkend="network_internal" />. Use this option only
              if you used the <option>--nic</option> option to enable
              internal networking for the specified virtual network
              card.
            </para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--nat-network<replaceable>N</replaceable>=<replaceable>network-name</replaceable></option></term>
          <listitem><para>
              Specifies the name of the NAT network to which this
              adapter is connected. Use this option only if the
              networking type is <literal>natnetwork</literal>, not
              <literal>nat</literal>.
            </para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--nic-generic-drv<replaceable>N</replaceable>=<replaceable>backend-driver</replaceable></option></term>
          <listitem><para>
              Enables you to access rarely used networking sub-modes,
              such as VDE networks and UDP Tunnel. Use this option only
              if you used the <option>--nic</option> option to enable
              generic networking for a virtual network card.
            </para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--mac-address<replaceable>N</replaceable>=auto | <replaceable>MAC-address</replaceable></option></term>
          <listitem><para>
              Specifies the MAC address of the specified network adapter
              on the VM. By default, &product-name; assigns a random MAC
              address to each network adapter at VM creation.
            </para></listitem>
        </varlistentry>
      </variablelist>
    </refsect2>
    <refsect2 id="vboxmanage-modifyvm-networking-nat">
      <title>NAT Networking Settings</title>
      <remark role="help-copy-synopsis"/>
      <para>
        The following options use <replaceable>N</replaceable> to
        specify the particular virtual network adapter to modify.
      </para>
      <variablelist>
        <varlistentry>
          <term><option>--nat-net<replaceable>N</replaceable>=default | <replaceable>network</replaceable></option></term>
          <listitem><para>
              Specifies the IP address range to use for this network.
              See <xref linkend="changenat" />. Use this option only if
              the networking type is <literal>nat</literal>, not
              <literal>natnetwork</literal>.
            </para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--nat-pf<replaceable>N</replaceable>=[<replaceable>name</replaceable>],tcp | udp,[<replaceable>host-IP</replaceable>],<replaceable>hostport</replaceable>,[<replaceable>guest-IP</replaceable>],<replaceable>guestport</replaceable></option></term>
          <listitem><para>
              Specifies the NAT port-forwarding rule to use. See
              <xref linkend="natforward" />.
            </para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--nat-pf<replaceable>N</replaceable>=delete <replaceable>name</replaceable></option></term>
          <listitem><para>
              Specifies the NAT port-forwarding rule to delete. See
              <xref linkend="natforward" />.
            </para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--nat-tftp-prefix<replaceable>N</replaceable>=<replaceable>prefix</replaceable></option></term>
          <listitem><para>
              Specifies a prefix to use for the built-in TFTP server.
              For example, you might use a prefix to indicate where the
              boot file is located. See <xref linkend="nat-tftp" /> and
              <xref linkend="nat-adv-tftp" />.
            </para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--nat-tftp-file<replaceable>N</replaceable>=<replaceable>boot-file</replaceable></option></term>
          <listitem><para>
              Specifies the name of the TFT boot file. See
              <xref linkend="nat-adv-tftp" />.
            </para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--nat-tftp-server<replaceable>N</replaceable>=<replaceable>tftp-server</replaceable></option></term>
          <listitem><para>
              Specifies the address of the TFTP server from which to
              boot. See <xref linkend="nat-adv-tftp" />.
            </para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--nat-bind-ip<replaceable>N</replaceable>=<replaceable>IP-address</replaceable></option></term>
          <listitem><para>
              Specifies an alternate IP address to which the NAT engine
              binds. See <xref linkend="nat-adv-settings" />. By
              default, &product-name;'s NAT engine routes TCP/IP packets
              through the default interface assigned by the host's
              TCP/IP stack.
            </para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--nat-dns-pass-domain<replaceable>N</replaceable>=on | off</option></term>
          <listitem><para>
              Specifies whether the built-in DHCP server passes the
              domain name for network name resolution.
            </para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--nat-dns-proxy<replaceable>N</replaceable>=on | off</option></term>
          <listitem><para>
              Specifies whether the NAT engine is the proxy for all
              guest DNS requests to the host system's DNS servers. See
              <xref linkend="nat-adv-dns" />.
            </para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--nat-dns-host-resolver<replaceable>N</replaceable>=on | off</option></term>
          <listitem><para>
              Specifies whether the NAT engine uses the host system's
              resolver mechanisms to handle DNS requests. See
              <xref linkend="nat-adv-dns" />.
            </para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--nat-localhostreachable<replaceable>N</replaceable>=on | off</option></term>
          <listitem><para>
              Specifies whether the NAT engine allows traffic from the guest directed to
              10.0.2.2 to pass to the host's loopback interface, i.e. localhost or 127.0.0.1.
            </para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--nat-settings<replaceable>N</replaceable>=[<replaceable>mtu</replaceable>],[<replaceable>socksnd</replaceable>],[<replaceable>sockrcv</replaceable>],[<replaceable>tcpsnd</replaceable>],[<replaceable>tcprcv</replaceable>]</option></term>
          <listitem><para>
              Specifies values for tuning NAT performance. See
              <xref linkend="nat-adv-settings" />.
            </para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--nat-alias-mode<replaceable>N</replaceable>=default | [log],[proxyonly],[sameports]</option></term>
          <listitem><para>
              Specifies the behavior of the NAT engine core as follows:
            </para><itemizedlist>
              <listitem><para>
                  <literal>log</literal> enables logging
                </para></listitem>
              <listitem><para>
                  <literal>proxyonly</literal> switches off aliasing
                  mode and makes NAT transparent
                </para></listitem>
              <listitem><para>
                  <literal>sameports</literal> enforces that the NAT
                  engine sends packets through the same port on which
                  they originated
                </para></listitem>
              <listitem><para>
                  <literal>default</literal> disables all aliasing modes
                </para></listitem>
            </itemizedlist><para>
              For more information, see
              <xref linkend="nat-adv-alias" />.
            </para></listitem>
        </varlistentry>
      </variablelist>
    </refsect2>
    <refsect2 id="vboxmanage-modifyvm-other-hardware">
      <title>Other Hardware Settings</title>
      <remark role="help-copy-synopsis"/>
      <para>
        The following options enable you to configure other hardware,
        such as the serial port, monitor, audio device, USB ports, and
        the clipboard, and drag-and-drop features.
      </para>
      <variablelist>
        <varlistentry>
          <term><option>--mouse=ps2 | usb | usbtablet | usbmultitouch | usbmtscreenpluspad</option></term>
          <listitem><para>
              Specifies the mode of the mouse to use in the VM. Valid
              values are: <literal>ps2</literal>,
              <literal>usb</literal>, <literal>usbtablet</literal>,
              <literal>usbmultitouch</literal> and
              <literal>usbmtscreenpluspad</literal>.
            </para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--keyboard=ps2 | usb</option></term>
          <listitem><para>
              Specifies the mode of the keyboard to use in the VM. Valid
              values are: <literal>ps2</literal> and
              <literal>usb</literal>.
            </para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--uart<replaceable>N</replaceable>=off | <replaceable>I/O-base</replaceable> <replaceable>IRQ</replaceable></option></term>
          <listitem><para>
              Configures virtual serial ports for the VM.
              <replaceable>N</replaceable> represents the serial port to
              modify. Valid values are <literal>off</literal> to disable
              the port or an I/O base address and IRQ. For information
              about the traditional COM port I/O base address and IRQ
              values, see <xref linkend="serialports" />.
            </para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--uart-mode<replaceable>N</replaceable>=<replaceable>mode</replaceable></option></term>
          <listitem><para>
              Specifies how &product-name; connects the specified
              virtual serial port to the host system that runs the VM.
              See <xref linkend="serialports" />.
            </para><para>
              Ensure that you first configure the virtual serial port by
              using the
              <option>--uart<replaceable>N</replaceable></option>
              option.
            </para><para>
              Specify one of the following connection modes for each
              port:
            </para><itemizedlist>
              <listitem><para>
                  <literal>disconnected</literal> indicates that even
                  though the serial port is shown to the guest VM, it is
                  not connected. This state is like a physical COM port
                  without a cable attached.
                </para></listitem>
              <listitem><para>
                  <literal>server</literal>
                  <replaceable>pipe-name</replaceable> creates the
                  specified named pipe or local domain socket on the
                  host system and connects the virtual serial device to
                  it.
                </para><para>
                  On a Windows host system,
                  <replaceable>pipe-name</replaceable> is a named pipe
                  that has a name that uses the following form:
                  <literal>\\.\pipe\<replaceable>pipe-name</replaceable></literal>.
                </para><para>
                  On a Linux host system,
                  <replaceable>pipe-name</replaceable> is a local domain
                  socket.
                </para></listitem>
              <listitem><para>
                  <literal>client</literal>
                  <replaceable>pipe-name</replaceable> connects the
                  virtual serial device to the specified named pipe or
                  local domain socket.
                </para><para>
                  Note that the named pipe or local domain socket must
                  already exist.
                </para></listitem>
              <listitem><para>
                  <literal>tcpserver</literal>
                  <replaceable>port</replaceable> creates a TCP socket
                  with the specified TCP port on the host system and
                  connects the virtual serial device to it.
                </para><para>
                  For UNIX-like systems, use ports over 1024 for
                  non-root users.
                </para></listitem>
              <listitem><para>
                  <literal>tcpclient</literal>
                  <replaceable>hostname</replaceable>:<replaceable>port</replaceable>
                  connects the virtual serial device to the TCP socket.
                </para><para>
                  Note that the TCP socket must already exist.
                </para></listitem>
              <listitem><para>
                  <literal>file</literal>
                  <replaceable>filename</replaceable> redirects the
                  serial port output to the specified raw file. Ensure
                  that <replaceable>filename</replaceable> is the
                  absolute path of the file on the host system.
                </para></listitem>
              <listitem><para>
                  <replaceable>device-name</replaceable>: specifies the
                  device name of a physical hardware serial port on the
                  specified host system to which the virtual serial port
                  connects.
                </para><para>
                  Use this mode to connect a physical serial port to a
                  VM.
                </para><para>
                  On a Windows host system, the device name is a COM
                  port such as <literal>COM1</literal>. On a Linux host
                  system, the device name is similar to
                  <filename>/dev/ttyS0</filename>.
                </para></listitem>
            </itemizedlist></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--uart-type<replaceable>N</replaceable>=<replaceable>UART-type</replaceable></option></term>
          <listitem><para>
              Configures the UART type for the specified virtual serial
              port (<replaceable>N</replaceable>). Valid values are
              <literal>16450</literal>, <literal>16550A</literal>, and
              <literal>16750</literal>. The default value is
              <literal>16550A</literal>.
            </para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--lpt-mode<replaceable>N</replaceable>=<replaceable>device-name</replaceable></option></term>
          <listitem><para>
              Specifies the device name of the parallel port to use.
            </para><para>
              For a Windows host system, use a device name such as
              <command>lpt1</command>. For a Linux host system, use a
              device name such as <filename>/dev/lp0</filename>.
            </para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--lpt<replaceable>N</replaceable>=<replaceable>I/O-base</replaceable> <replaceable>IRQ</replaceable></option></term>
          <listitem><para>
              Specifies the I/O base address and IRQ of the parallel
              port.
            </para><para>
              You can view the I/O base address and IRQ that the VM uses
              for the parallel port in the Device Manager.
            </para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--audio-controller=<replaceable>controller-type</replaceable></option></term>
          <listitem><para>
              Specifies the audio controller to be used with the VM.
              Valid audio controller type values are:
              <literal>ac97</literal>, <literal>hda</literal>, and
              <literal>sb16</literal>.
            </para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--audio-codec=<replaceable>codec-type</replaceable></option></term>
          <listitem><para>
              Specifies the audio codec to be used with the VM. Valid
              audio codec type values are: <literal>stac9700</literal>,
              <literal>ad1980</literal>, <literal>stac9221</literal>,
              and <literal>sb16</literal>.
            </para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--audio-driver=<replaceable>type</replaceable></option></term>
          <listitem><para>
              Specifies whether which audio driver (backend) to use.
              <literal>none</literal>, <literal>default</literal>,
              <literal>null</literal>, <literal>dsound</literal>,
              <literal>was</literal>, <literal>oss</literal>,
              <literal>alsa</literal>, <literal>pulse</literal>, and
              <literal>coreaudio</literal>.
            </para><para>
              Note that the audio driver are dependent on the host
              operating system. Use the <command>VBoxManage
              modifyvm</command> command usage output to determine the
              supported audio types for your host system.
            </para>
            <para>
              For maximum interoperability between hosts, the default
              audio driver can be used. The VM will then automatically select
              the most appropriate audio driver for the current host available.
            </para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--audio-enabled=on|off</option></term>
          <listitem><para>
              Specifies whether to enable or disable audio for the VM.
            </para>
            <para>
              This option has precedence over the --audio-on and --audio-off
              options, i.e. turning off audio via this option will turn off
              both, input and output, audio.
            </para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--audio-in=on|off</option></term>
          <listitem><para>
              Specifies whether to enable or disable audio capture from
              the host system.
            </para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--audio-out=on|off</option></term>
          <listitem><para>
              Specifies whether to enable or disable audio playback from
              the guest VM.
            </para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--clipboard-mode=<replaceable>value</replaceable></option></term>
          <listitem><para>
              Specifies how to share the guest VM or host system OS's
              clipboard with the host system or guest VM, respectively.
              Valid values are: <literal>disabled</literal>,
              <literal>hosttoguest</literal>,
              <literal>guesttohost</literal>, and
              <literal>bidirectional</literal>. See
              <xref linkend="generalsettings" />.
            </para><para>
              The clipboard feature is available only if you have the
              Guest Additions be installed in the VM.
            </para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--drag-and-drop=<replaceable>value</replaceable></option></term>
          <listitem><para>
              Specifies how to use the drag and drop feature between the
              host system and the VM. Valid values are:
              <literal>disabled</literal>,
              <literal>hosttoguest</literal>,
              <literal>guesttohost</literal>, and
              <literal>bidirectional</literal>. See
              <xref linkend="guestadd-dnd" />.
            </para><para>
              The drag and drop feature is available only if you have
              the Guest Additions be installed in the VM.
            </para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--monitor-count=<replaceable>count</replaceable></option></term>
          <listitem><para>
              Enables you to configure multiple monitors. See
              <xref linkend="settings-display" />.
            </para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--usb-ohci=on | off</option></term>
          <listitem><para>
              Enables or disables the VM's virtual USB 1.1 controller.
              See <xref linkend="settings-usb" />.
            </para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--usb-ehci=on | off</option></term>
          <listitem><para>
              Enables or disables the VM's virtual USB 2.0 controller.
              See <xref linkend="settings-usb" />.
            </para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--usb-xhci=on | off</option></term>
          <listitem><para>
              Enables or disables the VM's virtual USB 3.0 controller.
              This is the most efficient option if the VM supports it.
              See <xref linkend="settings-usb" />.
            </para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--usb-rename=<replaceable>old-name</replaceable> <replaceable>new-name</replaceable></option></term>
          <listitem><para>
              Rename's the VM's virtual USB controller from
              <replaceable>old-name</replaceable> to
              <replaceable>new-name</replaceable>.
            </para></listitem>
        </varlistentry>
      </variablelist>
    </refsect2>
    <refsect2 id="vboxmanage-modifyvm-recording">
      <title>Recording Settings</title>
      <remark role="help-copy-synopsis"/>
      <para>
        The following options enable you to modify settings for video
        recording, audio recording, or both.
      </para>
      <variablelist>
        <varlistentry>
          <term><option>--recording=on | off</option></term>
          <listitem><para>
              Enables or disables the recording of a VM session into a
              WebM or VP8 file. When set to <literal>on</literal>,
              recording begins when the VM session starts.
            </para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--recording-screens=all | none | <replaceable>screen-ID</replaceable>[,<replaceable>screen-ID</replaceable>...</option></term>
          <listitem><para>
              Enables you to specify the VM screens to record. The
              recording for each screen is output to its own file. Valid
              values are: <literal>all</literal>, which records all
              screens, <literal>none</literal>, which records no
              screens, or one or more specified screens.
            </para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--recording-file=<replaceable>filename</replaceable></option></term>
          <listitem><para>
              Specifies the name of the file in which to save the
              recording.
            </para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--recording-max-size=<replaceable>MB</replaceable></option></term>
          <listitem><para>
              Specifies the maximum size of the recorded video file in
              megabytes. When the file reaches the specified size,
              recording stops. If the value is <literal>0</literal>,
              recording continues until you manually stop recording.
            </para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--recording-max-time=<replaceable>seconds</replaceable></option></term>
          <listitem><para>
              Specifies the maximum amount of time to record in seconds.
              When the specified time elapses, recording stops. If the
              value is <literal>0</literal>, recording continues until
              you manually stop recording.
            </para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--recording-opts=<replaceable>keyword</replaceable>=<replaceable>value</replaceable></option></term>
          <listitem><para>
              Specifies additional video-recording properties as a
              comma-separated property keyword-value list. For example,
              <literal>foo=bar,a=b</literal>.
            </para><para>
              Only use this option if you are an advanced user. For
              information about keywords, see the <citetitle>Oracle VM
              VirtualBox Programming Guide and Reference</citetitle>.
            </para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--recording-video-fps=<replaceable>fps</replaceable></option></term>
          <listitem><para>
              Specifies the maximum number of video frames per second
              (FPS) to record. The recording ignores any frames that
              have a higher frequency. When you increase the FPS, fewer
              frames are ignored but the recording and the size of the
              recording file increases.
            </para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--recording-video-rate=<replaceable>bit-rate</replaceable></option></term>
          <listitem><para>
              Specifies the bit rate of the video in kilobits per
              second. When you increase the bit rate, the recording
              appearance improves and the size of the recording file
              increases.
            </para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--recording-video-res=<replaceable>width</replaceable>x<replaceable>height</replaceable></option></term>
          <listitem><para>
              Specifies the video resolution (width and height) of the
              recorded video in pixels.
            </para></listitem>
        </varlistentry>
      </variablelist>
    </refsect2>
    <refsect2 id="vboxmanage-modifyvm-vrde">
      <title>Remote Machine Settings</title>
      <remark role="help-copy-synopsis"/>
      <para>
        The following options enable you to modify the VirtualBox Remote
        Desktop Extension (VRDE) behavior.
      </para>
      <variablelist>
        <varlistentry>
          <term><option>--vrde=on | off</option></term>
          <listitem><para>
              Enables or disables the VRDE server.
            </para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--vrde-property=TCP/Ports=<replaceable>port</replaceable></option></term>
          <listitem><para>
              <replaceable>port</replaceable> is the port or port range
              to which the VRDE server binds. The
              <literal>default</literal> or <literal>0</literal> value
              uses port <literal>3389</literal>, which is the standard
              RDP port.
            </para><para>
              Also see the <option>--vrde-port</option> option
              description.
            </para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--vrde-property=TCP/Address=<replaceable>IP-address</replaceable></option></term>
          <listitem><para>
              <replaceable>IP-address</replaceable> is the IP address of
              the host network interface to which the VRDE server binds.
              When specified, the server accepts connections only on the
              host network interface at that IP address.
            </para><para>
              Also see the <option>--vrde-address</option> option
              description.
            </para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--vrde-property=VideoChannel/Enabled=<replaceable>value</replaceable></option></term>
          <listitem><para>
              Specifies whether the VRDP video channel is on or off.
              <literal>1</literal> means <literal>on</literal> and
              <literal>0</literal> means <literal>off</literal>. See
              <xref linkend="vrde-videochannel" />.
            </para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--vrde-property=Quality=<replaceable>value</replaceable></option></term>
          <listitem><para>
              Specifies a value between 10% and 100%, inclusive, that
              represents the JPEG compression level on the VRDE server
              video channel. A lower value produces lower JPEG quality
              but higher compression. See
              <xref linkend="vrde-videochannel" />.
            </para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--vrde-property=DownscaleProtection=<replaceable>value</replaceable></option></term>
          <listitem><para>
              Enables or disables the video downscale protection
              feature. Valid values are <literal>1</literal> to enable
              the feature and <literal>0</literal> to disable the
              feature.
            </para><para>
              When this feature is enabled, &product-name; determines
              whether to display the video:
            </para><itemizedlist>
              <listitem><para>
                  When the video size equals the size of the shadow
                  buffer, the video is considered to be full screen and
                  is displayed.
                </para></listitem>
              <listitem><para>
                  When the video size is between full screen and the
                  downscale threshold, the video is not displayed. Such
                  a video might be an application window, which is
                  unreadable when downscaled.
                </para></listitem>
            </itemizedlist><para>
              When this feature is disabled, an attempt is always made
              to display a video.
            </para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--vrde-property=Client/DisableDisplay=1</option></term>
          <listitem><para>
              Disables the display VRDE server feature.
            </para><para>
              To reenable a feature, assign an empty value. For example,
              to reenable the display feature, specify the
              <command>VBoxManage modifyvm
              --vrde-property=Client/DisableDisplay=</command> command.
              See <xref linkend="vrde-customization" />.
            </para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--vrde-property=DisableInput=1</option></term>
          <listitem><para>
              Disables the input VRDE server feature.
            </para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--vrde-property=DisableAudio=1</option></term>
          <listitem><para>
              Disables the audio VRDE server feature.
            </para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--vrde-property=DisableUSB=1</option></term>
          <listitem><para>
              Disables the USB VRDE server feature.
            </para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--vrde-property=Client/DisableClipboard=1</option></term>
          <listitem><para>
              Disables the clipboard VRDE server feature. To reenable
              the feature, assign an empty value. See
              <xref linkend="vrde-customization" />.
            </para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--vrde-property=DisableUpstreamAudio=1</option></term>
          <listitem><para>
              Disables the upstream audio VRDE server feature. To
              reenable the feature, assign an empty value. See
              <xref linkend="vrde-customization" />.
            </para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--vrde-property=Client/DisableRDPDR=1</option></term>
          <listitem><para>
              Disables the RDP device redirection for smart cards VRDE
              server feature. To reenable this feature, assign an empty
              value.
            </para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--vrde-property=H3DRedirect/Enabled=1</option></term>
          <listitem><para>
              Enables the 3D redirection VRDE server feature. To disable
              this feature, assign an empty value.
            </para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--vrde-property=Security/Method=<replaceable>value</replaceable></option></term>
          <listitem><para>
              Specifies the following information that is required for a
              connection:
            </para><itemizedlist>
              <listitem><para>
                  <literal>Negotiate</literal> indicates that both
                  Enhanced (TLS) and Standard RDP Security connections
                  are permitted. The security method is negotiated with
                  the client. This is the default value.
                </para></listitem>
              <listitem><para>
                  <literal>RDP</literal> indicates that only Standard
                  RDP Security is accepted.
                </para></listitem>
              <listitem><para>
                  <literal>TLS</literal> indicates that only Enhanced
                  RDP Security is accepted. The client must support TLS.
                </para></listitem>
            </itemizedlist><para>
              See <xref linkend="vrde-crypt" />.
            </para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--vrde-property=ServerCertificate=<replaceable>value</replaceable></option></term>
          <listitem><para>
              Specifies the absolute path to the server certificate. See
              <xref linkend="vrde-crypt" />.
            </para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--vrde-property=ServerPrivateKey=<replaceable>value</replaceable></option></term>
          <listitem><para>
              Specifies the absolute path to the server private key. See
              <xref linkend="vrde-crypt" />.
            </para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--vrde-property=CACertificate=<replaceable>value</replaceable></option></term>
          <listitem><para>
              Specifies the absolute path to the CA self-signed
              certificate. See <xref linkend="vrde-crypt" />.
            </para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--vrde-property Audio/RateCorrectionMode=<replaceable>value</replaceable></option></term>
          <listitem><para>
              Specifies the audio connection mode or the path to the
              audio log file. Valid values are as follows:
            </para><itemizedlist>
              <listitem><para>
                  <literal>VRDP_AUDIO_MODE_VOID</literal> is no mode.
                  Use this value to unset any set audio mode.
                </para></listitem>
              <listitem><para>
                  <literal>VRDP_AUDIO_MODE_RC</literal> is the rate
                  correction mode.
                </para></listitem>
              <listitem><para>
                  <literal>VRDP_AUDIO_MODE_LPF</literal> is the low pass
                  filter mode.
                </para></listitem>
              <listitem><para>
                  <literal>VRDP_AUDIO_MODE_CS</literal> is the client
                  sync sync mode to prevent an underflow or overflow of
                  the client queue.
                </para></listitem>
            </itemizedlist></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--vrde-property=LogPath=<replaceable>value</replaceable></option></term>
          <listitem><para>
              Specifies the absolute path to the audio log file.
            </para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--vrde-extpack=default | <replaceable>name</replaceable></option></term>
          <listitem><para>
              Specifies the library to use to access the VM remotely.
              The <literal>default</literal> value uses the RDP code
              that is part of the &product-name; Extension Pack.
            </para><para>
              To use the VRDE module in VNC, specify
              <literal>VNC</literal>. See
              <xref linkend="otherextpacks"/>.
            </para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--vrde-port=default | <replaceable>port</replaceable></option></term>
          <listitem><para>
              <replaceable>port</replaceable> is the port or port range
              to which the VRDE server binds. The
              <literal>default</literal> or <literal>0</literal> value
              uses port <literal>3389</literal>, which is the standard
              RDP port.
            </para><para>
              You can specify a comma-separated list of ports or port
              ranges of ports. Use a dash between two port numbers to
              specify a port range. The VRDE server binds to only one of
              the available ports from the list. Only one machine can
              use a given port at a time. For example, the
              <option>--vrde-port=5000,5010-5012</option> option
              specifies that server can bind to one of following ports:
              <literal>5000</literal>, <literal>5010</literal>,
              <literal>5011</literal>, or <literal>5012</literal>.
            </para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--vrde-address=<replaceable>IP-address</replaceable></option></term>
          <listitem><para>
              Specifies the IP address of the host network interface to
              which the VRDE server binds. If you specify an IP address,
              the server accepts connections only on the specified host
              network interface.
            </para><para>
              Use this option to specify whether the VRDP server should
              accept IPv4, IPv6, or both type of connections:
            </para><itemizedlist>
              <listitem><para>
                  <emphasis role="bold">Only IPv4:</emphasis> Use the
                  <option>--vrde-address="0.0.0.0"</option> option.
                </para></listitem>
              <listitem><para>
                  <emphasis role="bold">Only IPv6:</emphasis> Use the
                  <option>--vrde-address="::"</option> option.
                </para></listitem>
              <listitem><para>
                  <emphasis role="bold">Both IPv6 and IPv4:</emphasis>
                  Use the <option>--vrde-address=""</option>
                  option. This is the default value.
                </para></listitem>
            </itemizedlist></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--vrde-auth-type=null | external | guest</option></term>
          <listitem><para>
              Specify whether to use authorization and how to perform
              authorization. See <xref linkend="vbox-auth" />. Valid
              values are as follows:
            </para><itemizedlist>
              <listitem><para>
                  <literal>null</literal> provides no authentication.
                </para></listitem>
              <listitem><para>
                  <literal>external</literal> provides external
                  authentication through an authentication library.
                </para></listitem>
              <listitem><para>
                  <literal>guest</literal> performs authentication by
                  using guest user accounts. This unsupported method
                  requires that you install the Guest Additions on the
                  VM.
                </para></listitem>
            </itemizedlist></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--vrde-auth-library=default | <replaceable>name</replaceable></option></term>
          <listitem><para>
              Specifies the library to use for RDP authentication. The
              default library for external authentication is
              <filename>VBoxAuth</filename>. See
              <xref linkend="vbox-auth" />.
            </para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--vrde-multi-con=on | off</option></term>
          <listitem><para>
              Enables or disables the multiple connections VRDE server
              feature, if supported. See
              <xref linkend="vrde-multiconnection" />.
            </para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--vrde-reuse-con=on | off</option></term>
          <listitem><para>
              Specifies how the VRDE server behaves when multiple
              connections are disabled. When the value is
              <literal>on</literal>, the server permits a new client to
              connect and drops the existing connection. When the value
              is <literal>off</literal>, a new connection is not
              accepted if a client is already connected to the server.
              This is the default value.
            </para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--vrde-video-channel=on | off</option></term>
          <listitem><para>
              Enables video redirection if supported by the VRDE server.
              See <xref linkend="vrde-videochannel" />.
            </para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--vrde-video-channel-quality=<replaceable>percent</replaceable></option></term>
          <listitem><para>
              Specifies the image quality for video redirection as a
              value from 10 to 100 percent. The percentage represents
              the JPEG compression level where a lower number diminishes
              quality and provides higher compression. See
              <xref linkend="vrde-videochannel" />.
            </para></listitem>
        </varlistentry>
      </variablelist>
    </refsect2>
    <refsect2 id="vboxmanage-modifyvm-teleport">
      <title>Teleporting Settings</title>
      <remark role="help-copy-synopsis"/>
      <para>
        The following options enable you to configure a machine as a
        teleporting target. See <xref linkend="teleporting" /> and the
        teleporting related entries in <xref linkend="pot-insecure" />.
      </para>
      <variablelist>
        <varlistentry>
          <term><option>--teleporter=on | off</option></term>
          <listitem><para>
              Enables or disables the teleporter. When enabled, a
              machine starts up and waits to receive a teleporting
              request from the network instead of booting normally.
            </para><para>
              Teleporting requests are received on the port and address
              specified using the following parameters.
            </para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--teleporter-port=<replaceable>port</replaceable></option></term>
          <listitem><para>
              Specifies the port on which the VM listens to receive a
              teleporting request from another VM.
              <replaceable>port</replaceable> is any free TCP/IP port
              number, such as <literal>6000</literal>. You must also
              specify the <option>--teleporter</option> option.
            </para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--teleporter-address=<replaceable>IP-address</replaceable></option></term>
          <listitem><para>
              Specifies the IP address on which the VM listens to
              receive a teleporting request from another VM.
              <replaceable>IP-address</replaceable> is any IP address or
              host name and specifies the TCP/IP socket on which to
              bind. The default IP address is
              <literal>0.0.0.0</literal>, which represents any IP
              address. You must also specify the
              <option>--teleporter</option> option.
            </para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--teleporter-password=<replaceable>password</replaceable></option></term>
          <listitem><para>
              Specifies the password to use for authentication. When
              specified, the teleporting request only succeeds if the
              password on the source machine is the same password as the
              one you specify.
            </para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--teleporter-password-file=<replaceable>filename</replaceable></option></term>
          <listitem><para>
              Specifies a file that contains the password to use for
              authentication. When specified, the teleporting request
              only succeeds if the password on the source machine is the
              same password as the one you specify in the password file.
              A value of <literal>stdin</literal> reads the password
              from standard input.
            </para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--cpuid-portability-level=<replaceable>level</replaceable></option></term>
          <listitem>
            <para>
              Restricts the virtual CPU capabilities that &product-name;
              presents to the guest OS by using portability rules. Higher
              integer values designate more restrictive behavior. The
              default level of <literal>0</literal> indicates that all
              virtualized features supported by the host are made available
              to the guest. The value <literal>3</literal> supresses most
              features. Values of <literal>1</literal> and <literal>2</literal>
              represent restrictions in between. The behavior may change
              depending on the product version.
            </para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--cpuid-set=<replaceable>leaf</replaceable>[:<replaceable>subleaf</replaceable>]
              <replaceable>eax</replaceable>&nbsp;<replaceable>ebx</replaceable>&nbsp;<replaceable>ecx</replaceable>&nbsp;<replaceable>edx</replaceable></option></term>
          <listitem>
            <para>
              Advanced users can use this setting before a teleporting
              operation (in fact before starting the VM) to restrict the
              virtual CPU capabilities that &product-name; presents to
              the guest operating system. This must be run on both the
              source and the target machines involved in teleporting and
              will then modify what the guest sees when it executes the
              CPUID machine instruction. This might help with misbehaving
              applications that wrongly assume that certain CPU
              capabilities are present. The meaning of the parameters
              is hardware dependent. Refer to the AMD or Intel processor
              documentation.
            </para><para>
              The values of <replaceable>leaf</replaceable>,
              <replaceable>subleaf</replaceable> (optional),
              <replaceable>eax</replaceable>, <replaceable>ebx</replaceable>,
              <replaceable>ecx</replaceable> and <replaceable>edx</replaceable>
              are integers given in hexadecimal format, i.e. using a radix
              (base) of 16 without requiring any prefix.
            </para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--cpuid-remove=<replaceable>leaf</replaceable>[:<replaceable>subleaf</replaceable>]</option></term>
          <listitem>
            <para>
              Removes an adjustment established with <option>--cpuid-set</option>.
            </para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--cpuid-remove-all</option></term>
          <listitem>
            <para>
              Removes all adjustments established with <option>--cpuid-set</option>.
            </para></listitem>
        </varlistentry>
      </variablelist>
    </refsect2>
    <refsect2 id="vboxmanage-modifyvm-debugging">
      <title>Debugging Settings</title>
      <remark role="help-copy-synopsis"/>
      <para>
        Only use the following options to perform low-level VM
        debugging. These options are for advanced users only.
      </para>
      <variablelist>
        <varlistentry>
          <term><option>--tracing-enabled=on | off</option></term>
          <listitem><para>
              Enables or disables the trace buffer. Note that when
              specified, the trace buffer consumes some memory and adds
              overhead.
            </para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--tracing-config=<replaceable>config-string</replaceable></option></term>
          <listitem><para>
              Enables a tracing configuration that defines which group
              of trace points are enabled.
            </para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--tracing-allow-vm-access=on | off</option></term>
          <listitem><para>
              Enables or disables VM access to the trace buffer. The
              default value is <literal>off</literal>, which disables
              access.
            </para></listitem>
        </varlistentry>
      </variablelist>
    </refsect2>
    <refsect2 id="vboxmanage-modifyvm-usbcardreader">
      <title>USB Card Reader Settings</title>
      <remark role="help-copy-synopsis"/>
      <para>
        The following options specify the access to a USB Card Reader by
        the guest environment. A USB card reader can access data on
        memory cards, such as CompactFlash (CF), Secure Digital (SD),
        and MultiMediaCard (MMC).
      </para>
      <variablelist>
        <varlistentry>
          <term><option>--usb-card-reader=on | off</option></term>
          <listitem><para>
              Enables or disables the USB card reader interface.
            </para></listitem>
        </varlistentry>
      </variablelist>
    </refsect2>
    <refsect2 id="vboxmanage-modifyvm-autostart">
      <title>Autostarting VMs During Host System Boot</title>
      <para>
        The following options enable you to configure the VM autostart
        feature, which automatically starts the VM at host system
        boot-up. You must do some host system configuration before you
        can use this feature. See <xref linkend="autostart" />.
      </para>
      <remark role="help-copy-synopsis"/>
      <variablelist>
        <varlistentry>
          <term><option>--autostart-enabled=on | off</option></term>
          <listitem><para>
              Enables or disables VM autostart at host system boot-up
              for the specified users.
            </para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--autostart-delay=<replaceable>seconds</replaceable></option></term>
          <listitem><para>
              Specifies the number of seconds after host system boot-up
              to autostart the VM.
            </para></listitem>
        </varlistentry>
      </variablelist>
    </refsect2>
    <refsect2 id="vboxmanage-modifyvm-guest-debug">
      <title>Guest Debugging</title>
      <para>
        These options are for configuring the VMM for guest debugging.
      </para>
      <remark role="help-copy-synopsis"/>
      <variablelist>
        <varlistentry>
          <term><option>--guest-debug-provider=none | native | gdb | kd</option></term>
          <listitem><para>Selects the given debug stub provider. </para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--guest-debug-io-provider=none | tcp | udp | ipc</option></term>
          <listitem><para>Selects the given I/O transport backend for the selected provider.</para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--guest-debug-address=<replaceable>IP-Address</replaceable> | <replaceable>path</replaceable></option></term>
          <listitem><para>Sets the path the debugger is accessible under, depends on the selected I/O transport.</para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--guest-debug-port=<replaceable>port</replaceable></option></term>
          <listitem><para>Sets the port the debugger is accessible under, depends on the selected I/O transport.</para></listitem>
        </varlistentry>
      </variablelist>
    </refsect2>
    <refsect2 id="vboxmanage-modifyvm-pcipassthrough">
      <title>PCI Passthrough Settings</title>
      <para>
        The following options enable you to configure the PCI passthrough
        feature, which currently is not available in &product-name;. It is
        planned to bring this functionality back in the future.
      </para>
      <remark role="help-copy-synopsis"/>
      <variablelist>
        <varlistentry>
          <term><option>--pci-attach=<replaceable>host-PCI-address</replaceable>[@<replaceable>guest-PCI-bus-address</replaceable>]</option></term>
          <listitem><para>
              Attaches the specified PCI network controller on the host
              to the guest VM. You can optionally specify the PCI bus on
              the guest VM on which to attach the controller.
<!-- See <xref linkend="pcipassthrough" />. -->
            </para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--pci-detach=<replaceable>host-PCI-address</replaceable></option></term>
          <listitem><para>
              Detaches the specified PCI network controller from the
              attached PCI bus on the guest VM.
<!-- See <xref linkend="pcipassthrough" />. -->
            </para></listitem>
        </varlistentry>
      </variablelist>
    </refsect2>
    <refsect2 id="vboxmanage-modifyvm-testing">
      <title>Testing (ValidationKit / Bootsector)</title>
      <para>
        These options are for configuring the testing functionality of the VMM
        device and almost exclusively used by the bootsector testcases in the
        ValidationKit.
      </para>
      <remark role="help-copy-synopsis"/>
      <variablelist>
        <varlistentry>
          <term><option>--testing-enabled=on | off</option></term>
          <listitem><para>Enabled the testing functionality of the VMMDev. See VMMDevTesting.h for details. </para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--testing-mmio=on | off</option></term>
          <listitem><para>Enabled the MMIO region of the VMMDev testing feature.</para></listitem>
        </varlistentry>
        <varlistentry>
          <term><option>--testing-cfg-dword<replaceable>idx</replaceable>=<replaceable>value</replaceable></option></term>
          <listitem><para>
                This sets one of the 10 dword configuration values. The
                <replaceable>idx</replaceable> must be in the range 0 thru 9.
                The <replaceable>value</replaceable> is limited to 32 bits (dword).
            </para></listitem>
        </varlistentry>
      </variablelist>
    </refsect2>

  </refsect1>

  <refsect1>
    <title>Examples</title>
    <remark role="help-scope" condition="GLOBAL" />
    <para>
      The following command changes the description for the
      <filename>ol7</filename> VM.
    </para>
<screen>$ VBoxManage modifyvm ol7 --description "Oracle Linux 7 with UEK4"</screen>
    <para>
      The following command enables VirtualBox Remote Display Protocol
      (VRDP) support for the <filename>ol7</filename> VM.
    </para>
<screen>$ VBoxManage modifyvm ol7 --vrde on</screen>
  </refsect1>

  <refsect1>
    <title>See Also</title>
    <para>
      <xref linkend="vboxmanage-showvminfo" />,
      <xref linkend="vboxmanage-controlvm" />,
      <xref linkend="vboxmanage-createvm" />,
      <xref linkend="vboxmanage-startvm" />
      <xref linkend="vboxmanage-list" />
    </para>
  </refsect1>
</refentry>
