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. \"
. \" This file and its contents are supplied under the terms of the
. \" Common Development and Distribution License ("CDDL"), version 1.0.
. \" You may only use this file in accordance with the terms of version
. \" 1.0 of the CDDL.
. \"
. \" A full copy of the text of the CDDL should have accompanied this
. \" source. A copy of the CDDL is also available via the Internet at
. \" http://www.illumos.org/license/CDDL.
. \"
. \"
. \" Copyright 2014 Adam Stevko. All rights reserved.
. \" Copyright (c) 2015 by Delphix. All rights reserved.
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. \" Copyright (c) 2020 by AJ Jordan. All rights reserved.
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. \"
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.TH ARCSTAT 1 "May 7, 2020"
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.SH NAME
arcstat \- report ZFS ARC and L2ARC statistics
.SH SYNOPSIS
.LP
.nf
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\fB arcstat\fR [\fB -hvx\fR ] [\fB -f field[,field]...\fR ] [\fB -o file\fR ] [\fB -s string\fR ] [\fB interval\fR [\fB count\fR ]]
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.fi
.SH DESCRIPTION
.LP
The \fB arcstat\fR utility print various ZFS ARC and L2ARC statistics in
vmstat-like fashion.
.sp
.sp
.LP
The \fB arcstat\fR command reports the following information:
.sp
.ne 2
. \"
.sp
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.ne 1
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.na
\fB c \fR
.ad
.RS 14 n
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ARC target size
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.RE
.sp
.ne 2
.na
\fB dh% \fR
.ad
.RS 14 n
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Demand data hit percentage
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.RE
.sp
.ne 2
.na
\fB dm% \fR
.ad
.RS 14 n
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Demand data miss percentage
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.RE
.sp
.ne 2
.na
\fB mfu \fR
.ad
.RS 14 n
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MFU list hits per second
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.RE
.sp
.ne 2
.na
\fB mh% \fR
.ad
.RS 14 n
Metadata hit percentage
.RE
.sp
.ne 2
.na
\fB mm% \fR
.ad
.RS 14 n
Metadata miss percentage
.RE
.sp
.ne 2
.na
\fB mru \fR
.ad
.RS 14 n
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MRU list hits per second
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.RE
.sp
.ne 2
.na
\fB ph% \fR
.ad
.RS 14 n
Prefetch hits percentage
.RE
.sp
.ne 2
.na
\fB pm% \fR
.ad
.RS 14 n
Prefetch miss percentage
.RE
.sp
.ne 2
.na
\fB dhit \fR
.ad
.RS 14 n
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Demand data hits per second
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.RE
.sp
.ne 2
.na
\fB dmis \fR
.ad
.RS 14 n
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Demand data misses per second
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.RE
.sp
.ne 2
.na
\fB hit% \fR
.ad
.RS 14 n
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ARC hit percentage
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.RE
.sp
.ne 2
.na
\fB hits \fR
.ad
.RS 14 n
ARC reads per second
.RE
.sp
.ne 2
.na
\fB mfug \fR
.ad
.RS 14 n
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MFU ghost list hits per second
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.RE
.sp
.ne 2
.na
\fB mhit \fR
.ad
.RS 14 n
Metadata hits per second
.RE
.sp
.ne 2
.na
\fB miss \fR
.ad
.RS 14 n
ARC misses per second
.RE
.sp
.ne 2
.na
\fB mmis \fR
.ad
.RS 14 n
Metadata misses per second
.RE
.sp
.ne 2
.na
\fB mrug \fR
.ad
.RS 14 n
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MRU ghost list hits per second
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.RE
.sp
.ne 2
.na
\fB phit \fR
.ad
.RS 14 n
Prefetch hits per second
.RE
.sp
.ne 2
.na
\fB pmis \fR
.ad
.RS 14 n
Prefetch misses per second
.RE
.sp
.ne 2
.na
\fB read \fR
.ad
.RS 14 n
Total ARC accesses per second
.RE
.sp
.ne 2
.na
\fB time \fR
.ad
.RS 14 n
Time
.RE
.sp
.ne 2
.na
arcstat: add 'avail', fix 'free'
The meaning of the `free` field is currently `zfs_arc_sys_free`, which
is the target amount of memory to leave free for the system, and is
constant after booting.
This commit changes the meaning of `free` to arc_free_memory(), the
amount of memory that the ARC considers to be free.
It also adds a new arcstat field `avail`, which tracks
`arc_available_memory()`.
Since `avail` can be negative, it also updates the arcstat script to
pretty-print negative values.
example output:
$ arcstat -f time,miss,arcsz,c,grow,need,free,avail 1
time miss arcsz c grow need free avail
15:03:02 39K 114G 114G 0 0 2.4G 407M
15:03:03 42K 114G 114G 0 0 2.1G 120M
15:03:04 40K 114G 114G 0 0 1.8G -177M
15:03:05 24K 113G 112G 0 0 1.7G -269M
15:03:06 29K 111G 110G 0 0 1.6G -385M
15:03:07 27K 110G 108G 0 0 1.4G -535M
15:03:08 13K 108G 108G 0 0 2.2G 239M
15:03:09 33K 107G 107G 0 0 1.3G -639M
15:03:10 16K 105G 102G 0 0 2.6G 704M
15:03:11 7.2K 102G 102G 0 0 5.1G 3.1G
15:03:12 42K 103G 102G 0 0 4.8G 2.8G
Reviewed-by: George Melikov <mail@gmelikov.ru>
Reviewed-by: Pavel Zakharov <pavel.zakharov@delphix.com>
Reviewed-by: Tony Nguyen <tony.nguyen@delphix.com>
Signed-off-by: Matthew Ahrens <mahrens@delphix.com>
Closes #10494
2020-06-27 04:05:28 +03:00
\fB size \fR
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.ad
.RS 14 n
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ARC size
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.RE
arcstat: add 'avail', fix 'free'
The meaning of the `free` field is currently `zfs_arc_sys_free`, which
is the target amount of memory to leave free for the system, and is
constant after booting.
This commit changes the meaning of `free` to arc_free_memory(), the
amount of memory that the ARC considers to be free.
It also adds a new arcstat field `avail`, which tracks
`arc_available_memory()`.
Since `avail` can be negative, it also updates the arcstat script to
pretty-print negative values.
example output:
$ arcstat -f time,miss,arcsz,c,grow,need,free,avail 1
time miss arcsz c grow need free avail
15:03:02 39K 114G 114G 0 0 2.4G 407M
15:03:03 42K 114G 114G 0 0 2.1G 120M
15:03:04 40K 114G 114G 0 0 1.8G -177M
15:03:05 24K 113G 112G 0 0 1.7G -269M
15:03:06 29K 111G 110G 0 0 1.6G -385M
15:03:07 27K 110G 108G 0 0 1.4G -535M
15:03:08 13K 108G 108G 0 0 2.2G 239M
15:03:09 33K 107G 107G 0 0 1.3G -639M
15:03:10 16K 105G 102G 0 0 2.6G 704M
15:03:11 7.2K 102G 102G 0 0 5.1G 3.1G
15:03:12 42K 103G 102G 0 0 4.8G 2.8G
Reviewed-by: George Melikov <mail@gmelikov.ru>
Reviewed-by: Pavel Zakharov <pavel.zakharov@delphix.com>
Reviewed-by: Tony Nguyen <tony.nguyen@delphix.com>
Signed-off-by: Matthew Ahrens <mahrens@delphix.com>
Closes #10494
2020-06-27 04:05:28 +03:00
.sp
.ne 2
.na
\fB arcsz \fR
.ad
.RS 14 n
Alias for \fB size\fR
.RE
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.sp
.ne 2
.na
\fB dread \fR
.ad
.RS 14 n
Demand data accesses per second
.RE
.sp
.ne 2
.na
\fB eskip \fR
.ad
.RS 14 n
evict_skip per second
.RE
.sp
.ne 2
.na
\fB miss% \fR
.ad
.RS 14 n
ARC miss percentage
.RE
.sp
.ne 2
.na
\fB mread \fR
.ad
.RS 14 n
Metadata accesses per second
.RE
.sp
.ne 2
.na
\fB pread \fR
.ad
.RS 14 n
Prefetch accesses per second
.RE
.sp
.ne 2
.na
\fB l2hit% \fR
.ad
.RS 14 n
L2ARC access hit percentage
.RE
.sp
.ne 2
.na
\fB l2hits \fR
.ad
.RS 14 n
L2ARC hits per second
.RE
.sp
.ne 2
.na
\fB l2miss \fR
.ad
.RS 14 n
L2ARC misses per second
.RE
.sp
.ne 2
.na
\fB l2read \fR
.ad
.RS 14 n
Total L2ARC accesses per second
.RE
.sp
.ne 2
.na
\fB l2size \fR
.ad
.RS 14 n
Size of the L2ARC
.RE
.sp
.ne 2
.na
\fB mtxmis \fR
.ad
.RS 14 n
mutex_miss per second
.RE
.sp
.ne 2
.na
\fB l2bytes \fR
.ad
.RS 14 n
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Bytes read per second from the L2ARC
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.RE
.sp
.ne 2
.na
\fB l2miss% \fR
.ad
.RS 14 n
L2ARC access miss percentage
.RE
.sp
.ne 2
.na
\fB l2asize \fR
.ad
.RS 14 n
Actual (compressed) size of the L2ARC
.RE
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.sp
.ne 2
.na
\fB grow \fR
.ad
.RS 14 n
ARC grow disabled
.RE
.sp
.ne 2
.na
\fB need \fR
.ad
.RS 14 n
ARC reclaim needed
.RE
.sp
.ne 2
.na
\fB free \fR
.ad
.RS 14 n
arcstat: add 'avail', fix 'free'
The meaning of the `free` field is currently `zfs_arc_sys_free`, which
is the target amount of memory to leave free for the system, and is
constant after booting.
This commit changes the meaning of `free` to arc_free_memory(), the
amount of memory that the ARC considers to be free.
It also adds a new arcstat field `avail`, which tracks
`arc_available_memory()`.
Since `avail` can be negative, it also updates the arcstat script to
pretty-print negative values.
example output:
$ arcstat -f time,miss,arcsz,c,grow,need,free,avail 1
time miss arcsz c grow need free avail
15:03:02 39K 114G 114G 0 0 2.4G 407M
15:03:03 42K 114G 114G 0 0 2.1G 120M
15:03:04 40K 114G 114G 0 0 1.8G -177M
15:03:05 24K 113G 112G 0 0 1.7G -269M
15:03:06 29K 111G 110G 0 0 1.6G -385M
15:03:07 27K 110G 108G 0 0 1.4G -535M
15:03:08 13K 108G 108G 0 0 2.2G 239M
15:03:09 33K 107G 107G 0 0 1.3G -639M
15:03:10 16K 105G 102G 0 0 2.6G 704M
15:03:11 7.2K 102G 102G 0 0 5.1G 3.1G
15:03:12 42K 103G 102G 0 0 4.8G 2.8G
Reviewed-by: George Melikov <mail@gmelikov.ru>
Reviewed-by: Pavel Zakharov <pavel.zakharov@delphix.com>
Reviewed-by: Tony Nguyen <tony.nguyen@delphix.com>
Signed-off-by: Matthew Ahrens <mahrens@delphix.com>
Closes #10494
2020-06-27 04:05:28 +03:00
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 \fB avail\fR above zero, \fB avail\fR is usually more instructive to observe than \fB free\fR .
.RE
.sp
.ne 2
.na
\fB avail \fR
.ad
.RS 14 n
The ARC's idea of how much free memory is available to it, which is a bit less than \fB free\fR .
May temporarily be negative, in which case the ARC will reduce the target size \fB c\fR .
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.RE
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. \"
.SH OPTIONS
.LP
The following options are supported:
.sp
.ne 2
.na
\fB \fB -f\fR \fR
.ad
.RS 12 n
Display only specific fields. See \fB DESCRIPTION\fR for supported statistics.
.RE
.sp
.ne 2
.na
\fB \fB -h\fR \fR
.ad
.RS 12 n
Display help message.
.RE
.sp
.ne 2
.na
\fB \fB -o\fR \fR
.ad
.RS 12 n
Report statistics to a file instead of the standard output.
.RE
.sp
.ne 2
.na
\fB \fB -s\fR \fR
.ad
.RS 12 n
Display data with a specified separator (default: 2 spaces).
.RE
.sp
.ne 2
.na
\fB \fB -x\fR \fR
.ad
.RS 12 n
Print extended stats (same as -f time,mfu,mru,mfug,mrug,eskip,mtxmis,dread,pread,read).
.RE
.sp
.ne 2
.na
\fB \fB -v\fR \fR
.ad
.RS 12 n
Show field headers and definitions
.RE
.SH OPERANDS
.LP
The following operands are supported:
.sp
.ne 2
.na
\fB \fI count\fR \fR
.ad
.RS 12 n
Display only \fI count\fR reports.
.RE
.sp
.ne 2
.na
\fB \fI interval\fR \fR
.ad
.RS 12 n
Specify the sampling interval in seconds.
.RE
.SH AUTHORS
.LP
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arcstat was originally written in Perl by Neelakanth Nadgir and supported only ZFS ARC statistics.
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Mike Harsch updated it to support L2ARC statistics.
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John Hixson ported it to Python for FreeNAS over some beer, after which many individuals from the OpenZFS community continued to maintain and improve it.