docs: Cleanup vmstat.8

Made it follow the standard format and removed some cruft.
Added notes about you do need special permissions for some things
such as slabs.
This commit is contained in:
Craig Small 2023-01-18 17:35:44 +11:00
parent 0a5ccbdd42
commit bfe65a2cce

View File

@ -1,6 +1,13 @@
.\" This page Copyright (C) 1994 Henry Ware <al172@yfn.ysu.edu>
.\" Distributed under the GPL, Copyleft 1994.
.TH VMSTAT 8 "2020-06-04" "procps-ng" "System Administration"
.\"
.\" Copyright 1994 Henry Ware <al172@yfn.ysu.edu>
.\" 2011-2012 Sami Kerola <kerolasa@iki.fi>
.\" 2002-2023 Craig Small <csmall@dropbear.xyz>
.\" 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; either version 2 of the License, or
.\" (at your option) any later version.
.\"
.TH VMSTAT 8 "2023-01-18" "procps-ng" "System Administration"
.SH NAME
vmstat \- Report virtual memory statistics
.SH SYNOPSIS
@ -91,16 +98,13 @@ Display version information and exit.
\fB\-h\fR, \fB\-\-help\fR
Display help and exit.
.PD
.SH "FIELD DESCRIPTION FOR VM MODE"
.SS
.B "Procs"
.SH FIELD DESCRIPTION FOR VM MODE
.SS Procs
.nf
r: The number of runnable processes (running or waiting for run time).
b: The number of processes blocked waiting for I/O to complete.
.fi
.PP
.SS
.B "Memory"
.SS Memory
These are affected by the \fB\-\-unit\fR option.
.nf
swpd: the amount of swap memory used.
@ -110,31 +114,23 @@ cache: the amount of memory used as cache.
inact: the amount of inactive memory. (\fB\-a\fR option)
active: the amount of active memory. (\fB\-a\fR option)
.fi
.PP
.SS
.B "Swap"
.SS Swap
These are affected by the \fB\-\-unit\fR option.
.nf
si: Amount of memory swapped in from disk (/s).
so: Amount of memory swapped to disk (/s).
.fi
.PP
.SS
.B "IO"
.SS IO
.nf
bi: Kibibyte received from a block device (KiB/s).
bo: Kibibyte sent to a block device (KiB/s).
.fi
.PP
.SS
.B "System"
.SS System
.nf
in: The number of interrupts per second, including the clock.
cs: The number of context switches per second.
.fi
.PP
.SS
.B "CPU"
.SS CPU
These are percentages of total CPU time.
.nf
us: Time spent running non\-kernel code. (user time, including nice time)
@ -144,42 +140,38 @@ wa: Time spent waiting for IO. Prior to Linux 2.5.41, included in idle.
st: Time stolen from a virtual machine. Prior to Linux 2.6.11, unknown.
gu: Time spent running KVM guest code (guest time, including guest nice).
.fi
.PP
.SH "FIELD DESCRIPTION FOR DISK MODE"
.SS
.B "Reads"
.SH FIELD DESCRIPTION FOR DISK MODE
.SS Reads
.nf
total: Total reads completed successfully
merged: grouped reads (resulting in one I/O)
sectors: Sectors read successfully
ms: milliseconds spent reading
.fi
.PP
.SS
.B "Writes"
.SS Writes
.nf
total: Total writes completed successfully
merged: grouped writes (resulting in one I/O)
sectors: Sectors written successfully
ms: milliseconds spent writing
.fi
.PP
.SS
.B "IO"
.SS IO
.nf
cur: I/O in progress
s: seconds spent for I/O
.fi
.PP
.SH "FIELD DESCRIPTION FOR DISK PARTITION MODE"
.SH FIELD DESCRIPTION FOR DISK PARTITION MODE
.nf
reads: Total number of reads issued to this partition
read sectors: Total read sectors for partition
writes : Total number of writes issued to this partition
requested writes: Total number of write requests made for partition
.fi
.SH FIELD DESCRIPTION FOR SLAB MODE
Slab mode shows statistics per slab, for more information
about this information see
.BR slabinfo (5)
.PP
.SH "FIELD DESCRIPTION FOR SLAB MODE"
.nf
cache: Cache name
num: Number of currently active objects
@ -189,46 +181,18 @@ pages: Number of pages with at least one active object
.fi
.SH NOTES
.B vmstat
does not require special permissions.
.PP
These reports are intended to help identify system bottlenecks. Linux
.B vmstat
does not count itself as a running process.
.PP
All linux blocks are currently 1024 bytes. Old kernels may report blocks as
512 bytes, 2048 bytes, or 4096 bytes.
.PP
Since procps 3.1.9, vmstat lets you choose units (k, K, m, M). Default is K
(1024 bytes) in the default mode.
.PP
vmstat uses slabinfo 1.1
.SH FILES
.ta
.nf
/proc/meminfo
/proc/stat
/proc/*/stat
.fi
requires read access to files under \fI/proc\fR. The \fB\-m\fR requires read
access to \fI/proc/slabinfo\fR which may not be available to standard users.
Mount options for \fI/proc\fR such as \fIsubset=pid\fR may also impact what
is visible.
.SH "SEE ALSO"
.BR free (1),
.BR iostat (1),
.BR mpstat (1),
.BR ps (1),
.BR sar (1),
.BR top (1)
.PP
.SH BUGS
Does not tabulate the block io per device or count the number of system calls.
.SH AUTHORS
Written by
.UR al172@yfn.\:ysu.\:edu
Henry Ware
.UE .
.br
.UR ffrederick@users.\:sourceforge.\:net
Fabian Fr\('ed\('erick
.UE
(diskstat, slab, partitions...)
.BR top (1),
.BR slabinfo (5)
.SH "REPORTING BUGS"
Please send bug reports to
.UR procps@freelists.org