ARCSTAT(1)

NAME
arcstat - report ZFS ARC and L2ARC statistics

SYNOPSIS
arcstat [-havxp] [-f field[,field…]] [-o file] [-s string] [interval] [count]

DESCRIPTION
arcstat prints various ZFS ARC and L2ARC statistics in vmstat-like fashion:
c   ARC target size
dh% Demand hit percentage
di% Demand I/O hit percentage
dm% Demand miss percentage
ddh%
    Demand data hit percentage
ddi%
    Demand data I/O hit percentage
ddm%
    Demand data miss percentage
dmh%
    Demand metadata hit percentage
dmi%
    Demand metadata I/O hit percentage
dmm%
    Demand metadata miss percentage
mfu MFU list hits per second
mh% Metadata hit percentage
mi% Metadata I/O hit percentage
mm% Metadata miss percentage
mru MRU list hits per second
ph% Prefetch hits percentage
pi% Prefetch I/O hits percentage
pm% Prefetch miss percentage
pdh%
    Prefetch data hits percentage
pdi%
    Prefetch data I/O hits percentage
pdm%
    Prefetch data miss percentage
pmh%
    Prefetch metadata hits percentage
pmi%
    Prefetch metadata I/O hits percentage
pmm%
    Prefetch metadata miss percentage
dhit
    Demand hits per second
dioh
    Demand I/O hits per second
dmis
    Demand misses per second
ddhit
    Demand data hits per second
ddioh
    Demand data I/O hits per second
ddmis
    Demand data misses per second
dmhit
    Demand metadata hits per second
dmioh
    Demand metadata I/O hits per second
dmmis
    Demand metadata misses per second
hit%
    ARC hit percentage
hits
    ARC hits per second
ioh%
    ARC I/O hits percentage
iohs
    ARC I/O hits per second
mfug
    MFU ghost list hits per second
mhit
    Metadata hits per second
mioh
    Metadata I/O hits per second
miss
    ARC misses per second
mmis
    Metadata misses per second
mrug
    MRU ghost list hits per second
phit
    Prefetch hits per second
pioh
    Prefetch I/O hits per second
pmis
    Prefetch misses per second
pdhit
    Prefetch data hits per second
pdioh
    Prefetch data I/O hits per second
pdmis
    Prefetch data misses per second
pmhit
    Prefetch metadata hits per second
pmioh
    Prefetch metadata I/O hits per second
pmmis
    Prefetch metadata misses per second
read
    Total ARC accesses per second
time
    Current time
size
    ARC size
arcsz
    Alias for size
unc Uncached list hits per second
dread
    Demand accesses per second
ddread
    Demand data accesses per second
dmread
    Demand metadata accesses per second
eskip
    evict_skip per second
miss%
    ARC miss percentage
mread
    Metadata accesses per second
pread
    Prefetch accesses per second
pdread
    Prefetch data accesses per second
pmread
    Prefetch metadata accesses per second
l2hit%
    L2ARC access hit percentage
l2hits
    L2ARC hits per second
l2miss
    L2ARC misses per second
l2read
    Total L2ARC accesses per second
l2pref
    L2ARC prefetch allocated size per second
l2pref%
    L2ARC prefetch allocated size percentage
l2mfu
    L2ARC MFU allocated size per second
l2mfu%
    L2ARC MFU allocated size percentage
l2mru
    L2ARC MRU allocated size per second
l2mru%
    L2ARC MRU allocated size percentage
l2data
    L2ARC data (buf content) allocated size per second
l2data%
    L2ARC data (buf content) allocated size percentage
l2meta
    L2ARC metadata (buf content) allocated size per second
l2meta%
    L2ARC metadata (buf content) allocated size percentage
l2size
    Size of the L2ARC
mtxmis
    mutex_miss per second
l2bytes
    Bytes read per second from the L2ARC
l2wbytes
    Bytes written per second to the L2ARC
l2miss%
    L2ARC access miss percentage
l2asize
    Actual (compressed) size of the L2ARC
cmpsz
    Compressed size
cmpsz%
    Compressed size percentage
ovhsz
    Overhead size
ovhsz%
    Overhead size percentage
bonsz
    Bonus size
bonsz%
    Bonus size percentage
dnosz
    Dnode size
dnosz%
    Dnode size percentage
dbusz
    Dbuf size
dbusz%
    Dbuf size percentage
hdrsz
    Header size
hdrsz%
    Header size percentage
l2hsz
    L2 header size
l2hsz%
    L2 header size percentage
abdsz
    ABD chunk waste size
abdsz%
    ABD chunk waste size percentage
datatg
    ARC data target
datatg%
    ARC data target percentage
datasz
    ARC data size
datasz%
    ARC data size percentage
metatg
    ARC metadata target
metatg%
    ARC metadata target percentage
metasz
    ARC metadata size
metasz%
    ARC metadata size percentage
anosz
    Anonymous size
anosz%
    Anonymous size percentage
anoda
    Anonymous data size
anoda%
    Anonymous data size percentage
anome
    Anonymous metadata size
anome%
    Anonymous metadata size percentage
anoed
    Anonymous evictable data size
anoed%
    Anonymous evictable data size percentage
anoem
    Anonymous evictable metadata size
anoem%
    Anonymous evictable metadata size percentage
mfutg
    MFU target
mfutg%
    MFU target percentage
mfudt
    MFU data target
mfudt%
    MFU data target percentage
mfumt
    MFU metadata target
mfumt%
    MFU metadata target percentage
mfusz
    MFU size
mfusz%
    MFU size percentage
mfuda
    MFU data size
mfuda%
    MFU data size percentage
mfume
    MFU metadata size
mfume%
    MFU metadata size percentage
mfued
    MFU evictable data size
mfued%
    MFU evictable data size percentage
mfuem
    MFU evictable metadata size
mfuem%
    MFU evictable metadata size percentage
mfugsz
    MFU ghost size
mfugd
    MFU ghost data size
mfugm
    MFU ghost metadata size
mrutg
    MRU target
mrutg%
    MRU target percentage
mrudt
    MRU data target
mrudt%
    MRU data target percentage
mrumt
    MRU metadata target
mrumt%
    MRU metadata target percentage
mrusz
    MRU size
mrusz%
    MRU size percentage
mruda
    MRU data size
mruda%
    MRU data size percentage
mrume
    MRU metadata size
mrume%
    MRU metadata size percentage
mrued
    MRU evictable data size
mrued%
    MRU evictable data size percentage
mruem
    MRU evictable metadata size
mruem%
    MRU evictable metadata size percentage
mrugsz
    MRU ghost size
mrugd
    MRU ghost data size
mrugm
    MRU ghost metadata size
uncsz
    Uncached size
uncsz%
    Uncached size percentage
uncda
    Uncached data size
uncda%
    Uncached data size percentage
uncme
    Uncached metadata size
uncme%
    Uncached metadata size percentage
unced
    Uncached evictable data size
unced%
    Uncached evictable data size percentage
uncem
    Uncached evictable metadata size
uncem%
    Uncached evictable metadata size percentage
grow
    ARC grow disabled
need
    ARC reclaim needed
free
    The ARC's idea of how much free memory there is, which includes evictable memory in the page cache. Since the ARC tries to keep avail above zero, avail is usually more instructive to observe than free.
avail
    The ARC's idea of how much free memory is available to it, which is a bit less than free. May temporarily be negative, in which case the ARC will reduce the target size c.

OPTIONS

-a  Print all possible stats.

-f  Display only specific fields. See DESCRIPTION for supported statistics.

-h  Display help message.

-o  Report statistics to a file instead of the standard output.

-p  Disable auto-scaling of numerical fields (for raw, machine-parsable values).

-s  Display data with a specified separator (default: 2 spaces).

-x  Print extended stats (same as -f time,mfu,mru,mfug,mrug,eskip,mtxmis,dread,pread,read).

-v  Show field headers and definitions

OPERANDS
The following operands are supported:
interval
    Specify the sampling interval in seconds.
count
    Display only count reports.