vmstat(1)						      General Commands Manual							 vmstat(1)

NAME

       vmstat - report virtual memory statistics

SYNOPSIS

       [interval [count]]

       | |

DESCRIPTION

       The  command  reports certain statistics kept about process, virtual memory, trap, and CPU activity.  It also can clear the accumulators in
       the kernel structure.

   Options
       recognizes the following options:

	      Report disk transfer information as a separate section,
			in the form of transfers per second.

	      Provide an output format
			that is more easily viewed on an 80-column display device.  This format separates the default output into two groups: vir-
			tual  memory  information and CPU data.  Each group is displayed as a separate line of output.	On multiprocessor systems,
			this display format also provides CPU utilization on a per CPU basis for the active processors.

	      Report the number of processes swapped in and out
			and instead of page reclaims and address translation faults and

	      interval	Display successive lines which are summaries over the last interval seconds.  The first line  reported	is  for  the  time
			since  a reboot and each subsequent line is for the last interval only.  If interval is zero, the output is displayed once
			only.  If the option is specified, the column headers are repeated.  If is omitted, the column headers are not repeated.

			The command prints 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.

	      count	Repeat the summary statistics count times.  If count is omitted or zero, the output is repeated until an interrupt or quit
			signal is received.  From the terminal, these are commonly and respectively (see stty(1)).

	      Report on the number of forks
			and the number of pages of virtual memory involved since boot-up.

	      Print the total number of several kinds of paging-related events
			from the kernel structure that have occurred since boot-up or since was last executed with the option.

	      Clear all accumulators in the kernel
			structure.  This option is restricted to the super user.

       If none of these options is given, displays a one-line summary of the virtual memory activity since boot-up or since the  option  was  last
       executed.

   Column Descriptions
       The column headings and the meaning of each column are:

	      Information about numbers of processes in various states.

			       In run queue

			       Blocked for resources (I/O, paging, etc.)

			       Runnable or short sleeper (< 20 secs) but swapped

	      Information about the usage of virtual and real memory.
			  Virtual pages are considered active if they belong to processes that are running or have run in the last 20 seconds.

			       Active virtual pages

			       Size of the free list

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

			       Page reclaims (without

			       Address translation faults (without

			       Processes swapped in (with

			       Processes swapped out (with

			       Pages paged in

			       Pages paged out

			       Pages freed per second

			       Anticipated short term memory shortfall

			       Pages scanned by clock algorithm, per second

	      Trap/interrupt rate averages per second over last 5 seconds.

			       Device interrupts per second (nonclock)

			       System calls per second

			       CPU context switch rate (switches/sec)

	      Breakdown of percentage usage of CPU time for the active processors

			       User time for normal and low priority processes

			       System time

			       CPU idle

EXAMPLES

       The following examples show the output for various command options.  For formatting purposes, some leading blanks have been deleted.

       1.     Display the default output.

       2.     Add the disk tranfer information to the default output.

       3.     Display the default output in 80-column format.

       4.     Replace the page reclaims and address translation faults with process swapping in the default output.

       5.     Display the default output twice at five-second intervals.  Note that the headers are repeated.

       6.     Display the default output twice in 80-column format at five-second intervals.  Note that the headers are repeated.

       7.     Display the default output and disk transfers twice in 80-column format at five-second intervals.  Note that the headers repeated.

       8.     Display the number of forks and pages of virtual memory since boot-up.

       9.     Display the counts of paging-related events.

WARNINGS

       Users  of must not rely on the exact field widths and spacing of its output, as these will vary depending on the system, the release of HP-
       UX, and the data to be displayed.

AUTHOR

       was developed by the University of California, Berkeley and HP.

SEE ALSO

       iostat(1).

																	 vmstat(1)