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NAME    [Toc]    [Back]

       vmstat - Report virtual memory statistics

SYNOPSIS    [Toc]    [Back]

       vmstat [-n] [delay [ count]]

DESCRIPTION    [Toc]    [Back]

       vmstat  reports	information about processes, memory, paging, block IO,
       traps, and cpu activity.

       The first report produced gives averages since the last reboot.	 Additional
  reports	give information on a sampling period of length delay.
       The process and memory reports are instantaneous in either case.

   Options    [Toc]    [Back]
       The -n switch  causes the header to be displayed only once rather  than

       delay  is  the delay between updates in seconds.  If no delay is specified,
 only one report is printed with the average values since boot.

       count is the number of updates.	If no count is specified and delay  is
       defined, count defaults to infinity.

       The -V switch results in displaying version information.


       r: The number of processes waiting for run time.
       b: The number of processes in uninterruptable sleep.
       w: The number of processes swapped out but otherwise runnable.  This
	  field is calculated, but Linux never desperation swaps.

   Memory    [Toc]    [Back]
       swpd: the amount of virtual memory used (kB).
       free: the amount of idle memory (kB).
       buff: the amount of memory used as buffers (kB).

   Swap    [Toc]    [Back]
       si: Amount of memory swapped in from disk (kB/s).
       so: Amount of memory swapped to disk (kB/s).

   IO    [Toc]    [Back]
       bi: Blocks sent to a block device (blocks/s).
       bo: Blocks received from a block device (blocks/s).

   System    [Toc]    [Back]
       in: The number of interrupts per second, including the clock.
       cs: The number of context switches per second.

   CPU    [Toc]    [Back]
       These are percentages of total CPU time.
       us: user time
       sy: system time
       id: idle time

NOTES    [Toc]    [Back]

       vmstat does not require special permissions.

       These  reports are intended to help identify system bottlenecks.  Linux
       vmstat does not count itself as a running process.

       All linux blocks are currently 1k, except for CD-ROM blocks  which  are

FILES    [Toc]    [Back]


SEE ALSO    [Toc]    [Back]

       ps(1), top(1), free(1)

BUGS    [Toc]    [Back]

       Does not tabulate the block io per device or count the number of system

AUTHOR    [Toc]    [Back]

       Written by Henry Ware <al172@yfn.ysu.edu>.

Throatwobbler Ginkgo Labs	 27 July 1994			     VMSTAT(8)
[ Back ]
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