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 data hit percentage
dm%: Demand data miss percentage
mfu: MFU list hits per second
mh%: Metadata hit percentage
mm%: Metadata miss percentage
mru: MRU list hits per second
ph%: Prefetch hits percentage
pm%: Prefetch miss percentage
dhit: Demand data hits per second
dmis: Demand data misses per second
hit%: ARC hit percentage
hits: ARC reads per second
mfug: MFU ghost list hits per second
mhit: Metadata 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
pmis: Prefetch misses per second
read: Total ARC accesses per second
time: Current time
size: ARC size
arcsz: Alias for size
dread: Demand data accesses per second
eskip: evict_skip per second
miss%: ARC miss percentage
mread: Metadata accesses per second
pread: Prefetch 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
l2miss%: L2ARC access miss percentage
l2asize: Actual (compressed) size of the L2ARC
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.