ARCSTAT(8) Maintenance Commands and Procedures ARCSTAT(8)

NAME

arcstat - report ZFS ARC and L2ARC statistics

SYNOPSIS

arcstat [-hvxr] [-f field[,field]...] [-o file] [-s string]
[interval [count]]

DESCRIPTION

The arcstat utility print various ZFS ARC and L2ARC statistics in
vmstat-like fashion.


The arcstat command reports the following information:


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
Time


arcsz
ARC 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

OPTIONS

The following options are supported:


-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.


-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:

count
Display only count reports.


interval
Specify the sampling interval in seconds.

AUTHORS

arcstat was originally written by Neelakanth Nadgir and supported
only ZFS ARC statistics. Mike Harsch updated it to support L2ARC
statistics.

February 4, 2014 ARCSTAT(8)