.\" This page Copyright (C) 1994 Henry Ware <al172@yfn.ysu.edu>
.\" Distributed under the GPL, Copyleft 1994.
-.TH VMSTAT 8 "2009 Jan 9" "Throatwobbler Ginkgo Labs" "Linux Administrator's Manual"
+.TH VMSTAT 8 "September 2011" "procps-ng" "System Administration"
.SH NAME
vmstat \- Report virtual memory statistics
.SH SYNOPSIS
-.ft B
.B vmstat
-.RB [ "\-a" ]
-.RB [ "\-n" ]
-.RI [ delay " [ " count ]]
-.br
-.B vmstat
-.RB [ "\-f" ]
-.RB [ "\-s" ]
-.RB [ "\-m" ]
-.br
-.B vmstat
-.RB [ "\-S unit"]
-.br
-.B vmstat
-.RB [ "\-d"]
-.br
-.B vmstat
-.RB [ "\-D"]
-.br
-.B vmstat
-.RB [ "\-p disk partition"]
-.br
-.B vmstat
-.RB [ "\-V" ]
+[options]
+.RI [ delay " [" count ]]
.SH DESCRIPTION
-\fBvmstat\fP reports information about processes, memory, paging,
-block IO, traps, disks and cpu activity.
-
+.B vmstat
+reports information about processes, memory, paging, block IO, traps, disks
+and cpu activity.
+.PP
The first report produced gives averages since the last reboot. Additional
-reports give information on a sampling period of length \fIdelay\fP.
+reports give information on a sampling period of length
+.IR delay .
The process and memory reports are instantaneous in either case.
-
-.SS Options
-The \fB\-a\fP switch displays active/inactive memory, given a 2.5.41 kernel or better.
-.PP
-The \fB\-f\fP switch displays the number of forks since boot.
-This includes the fork, vfork, and clone system calls, and is
-equivalent to the total number of tasks created. Each process
-is represented by one or more tasks, depending on thread usage.
-This display does not repeat.
-.PP
-The \fB\-m\fP displays slabinfo.
-.PP
-The \fB\-n\fP switch causes the header to be displayed only once rather than periodically.
-.PP
-The \fB\-s\fP switch displays a table of various event counters
-and memory statistics. This display does not repeat.
-.PP
+.SH OPTIONS
+.TP
.I delay
-is the delay between updates in seconds. If no delay is specified,
-only one report is printed with the average values since boot.
-.PP
+The
+.I delay
+between updates in seconds. If no
+.I delay
+is specified, only one report is printed with the average values since boot.
+.TP
.I count
-is the number of updates. If no count is specified and delay is
-defined, \fIcount\fP defaults to infinity.
-.PP
-The \fB\-d\fP reports disk statistics (2.5.70 or above required)
-.PP
-The \fB-D\fP reports some summary statistics about disk activity.
-.PP
-The \fB\-p\fP followed by some partition name for detailed statistics (2.5.70 or above required)
-.PP
-The \fB\-S\fP followed by k or K or m or M switches outputs between
-1000, 1024, 1000000, or 1048576 bytes. Note this does not change the
-swap (si/so) or block (bi/bo) fields.
-.PP
-The \fB\-V\fP switch results in displaying version information.
-.PP
-.SH FIELD DESCRIPTION FOR VM MODE
+Number of updates. In absense of
+.IR count ,
+when
+.I delay
+is defined, default is infinite.
+.TP
+\fB\-a\fR, \fB\-\-active\fR
+Display active and inactive memory, given a 2.5.41 kernel or better.
+.TP
+\fB\-f\fR, \fB\-\-forks\fR
+The
+.B \-f
+switch displays the number of forks since boot. This includes the fork,
+vfork, and clone system calls, and is equivalent to the total number of tasks
+created. Each process is represented by one or more tasks, depending on
+thread usage. This display does not repeat.
+.TP
+\fB\-m\fR, \fB\-\-slabs\fR
+Displays slabinfo.
+.TP
+\fB\-n\fR, \fB\-\-one-header\fR
+Display the header only once rather than periodically.
+.TP
+\fB\-s\fR, \fB\-\-stats\fR
+Displays a table of various event counters and memory statistics. This
+display does not repeat.
+.TP
+\fB\-d\fR, \fB\-\-disk\fR
+Report disk statistics (2.5.70 or above required).
+.TP
+\fB\-D\fR, \fB\-\-disk-sum\fR
+Report some summary statistics about disk activity.
+.TP
+\fB\-p\fR, \fB\-\-partition\fR \fIdevice\fR
+Detailed statistics about partition (2.5.70 or above required).
+.TP
+\fB\-S\fR, \fB\-\-unit\fR \fIcharacter\fR
+Switches outputs between 1000
+.RI ( k ),
+1024
+.RI ( K ),
+1000000
+.RI ( m ),
+or 1048576
+.RI ( M )
+bytes. Note this does not change the swap (si/so) or block (bi/bo)
+fields.
+.TP
+\fB\-V\fR, \fB\-\-version\fR
+Display version information and exit.
+.TP
+\fB\-h\fR, \fB\-\-help\fR
+Display help and exit.
+.PD
+.SH "FIELD DESCRIPTION FOR VM MODE"
.SS
.B "Procs"
.nf
-r: The number of processes waiting for run time.
+r: The number of processes waiting for run time.
b: The number of processes in uninterruptible sleep.
.fi
.PP
free: the amount of idle memory.
buff: the amount of memory used as buffers.
cache: the amount of memory used as cache.
-inact: the amount of inactive memory. (\-a option)
-active: the amount of active memory. (\-a option)
+inact: the amount of inactive memory. (\-a option)
+active: the amount of active memory. (\-a option)
.fi
.PP
.SS
.fi
.PP
.SS
-.B "CPU "
+.B "CPU"
These are percentages of total CPU time.
.nf
-us: Time spent running non\-kernel code. (user time, including nice time)
-sy: Time spent running kernel code. (system time)
-id: Time spent idle. Prior to Linux 2.5.41, this includes IO\-wait time.
-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.
+us: Time spent running non\-kernel code. (user time, including nice time)
+sy: Time spent running kernel code. (system time)
+id: Time spent idle. Prior to Linux 2.5.41, this includes IO\-wait time.
+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.
.fi
.PP
-.SH FIELD DESCRIPTION FOR DISK MODE
+.SH "FIELD DESCRIPTION FOR DISK MODE"
.SS
.B "Reads"
.nf
-total: Total reads completed successfully
+total: Total reads completed successfully
merged: grouped reads (resulting in one I/O)
sectors: Sectors read successfully
ms: milliseconds spent reading
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
-
.PP
-.SH FIELD DESCRIPTION FOR SLAB MODE
+.SH "FIELD DESCRIPTION FOR SLAB MODE"
.nf
cache: Cache name
num: Number of currently active objects
size: Size of each object
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 "
+.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.
+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
+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 FIXME
+vmstat uses slabinfo 1.1
.SH FILES
.ta
.nf
/proc/stat
/proc/*/stat
.fi
-
.SH "SEE ALSO"
+.BR free (1),
.BR iostat (1),
-.BR sar (1),
.BR mpstat (1),
.BR ps (1),
-.BR top (1),
-.BR free (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
-.nf
-Written by Henry Ware <al172@yfn.ysu.edu>.
-Fabian Fr\('ed\('erick <ffrederick@users.sourceforge.net> (diskstat, slab, partitions...)
+Written by
+.UR al172\@yfn.\:ysu.\:edu
+Henry Ware
+.UE .
+.br
+.UR ffrederick\@users.\:sourceforge.\:net
+Fabian Fr\('ed\('erick
+.UE
+(diskstat, slab, partitions...)
+.SH "REPORTING BUGS"
+Please send bug reports to
+.UR procps\@freelists.org
+.UE
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