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BSD 2.11 - man page for vmstat (bsd section 1)

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VMSTAT(1)										VMSTAT(1)

NAME
       vmstat - report virtual memory statistics

SYNOPSIS
       vmstat [ -fsi ] [ drives ] [ interval [ count ] ]

DESCRIPTION
       Vmstat  delves into the system and normally reports certain statistics kept about process,
       virtual memory, disk, trap and cpu activity.  If given a -f argument, it  instead  reports
       on  the number of forks and vforks since system startup and the number of pages of virtual
       memory involved in each kind of fork.  If given a -s argument, it instead prints the  con-
       tents  of  the  sum  structure, giving the total number of several kinds of paging related
       events which have occurred since boot.  If given a -i argument, it instead reports on  the
       number of interrupts taken by each device since system startup.

       If  none of these options are given, vmstat will report in the first line a summary of the
       virtual memory activity since the system has been booted.  If interval is specified,  then
       successive  lines  are  summaries over the last interval seconds.  ``vmstat 5'' will print
       what the system is doing every five seconds; this is a good choice  of  printing  interval
       since  this  is	how  often  some of the statistics are sampled in the system; others vary
       every second, running the output for a while will make it apparent  which  are  recomputed
       every  second.	If a count is given, the statistics are repeated count times.  The format
       fields are:

       Procs: information about numbers of processes in various states.

       r    in run queue
       b    blocked for resources (i/o, paging, etc.)
       w    runnable or short sleeper (< 20 secs) but swapped

       Memory: information about the usage of virtual and real memory.	Virtual pages are consid-
       ered  active if they belong to processes which are running or have run in the last 20 sec-
       onds.  A ``page'' here is 1024 bytes.

       avm  active virtual pages
       fre  size of the free list

       Page: information about page faults and paging activity.  These	are  averaged  each  five
       seconds, and given in units per second.

       re   page reclaims (simulating reference bits)
       at   pages attached (found in free list)
       pi   pages paged in
       po   pages paged out
       fr   pages freed per second
       de   anticipated short term memory shortfall
       sr   pages scanned by clock algorithm, per-second

       up/hp/rk/ra:  Disk operations per second (this field is system dependent).  Typically pag-
       ing will be split across several of the available drives.  The number under each of  these
       is the unit number.

       Faults: trap/interrupt rate averages per second over last 5 seconds.

       in   (non clock) device interrupts per second
       sy   system calls per second
       cs   cpu context switch rate (switches/sec)

       Cpu: breakdown of percentage usage of CPU time

       us   user time for normal and low priority processes
       sy   system time
       id   cpu idle

       If  more than 4 disk drives are configured in the system, vmstat displays only the first 4
       drives, with priority given to Massbus disk drives (i.e. if both Unibus and Massbus drives
       are  present  and  the total number of drives exceeds 4, then some number of Unibus drives
       will not be displayed in favor of the Massbus drives).  To force vmstat	to  display  spe-
       cific drives, their names may be supplied on the command line.

FILES
       /dev/kmem, /vmunix

SEE ALSO
       systat(1), iostat(1)

       The  sections  starting	with ``Interpreting system activity'' in Installing and Operating
       4.2bsd.

4th Berkeley Distribution		  March 15, 1986				VMSTAT(1)
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