vmstat.1 (2010 09)

v
vmstat(1) vmstat(1)
NAME
vmstat - report virtual memory statistics
SYNOPSIS
vmstat [-dnS][interval [count ]]
vmstat -f  -s  -z
DESCRIPTION
The vmstat command reports certain statistics kept about process, virtual memory, trap, and CPU
activity. It also can clear the accumulators in the kernel
sum structure.
Options
vmstat recognizes the following options:
-d Report disk transfer information as a separate section, in the form of transfers per
second.
-n Provide an output format that is more easily viewed on an 80-column display device.
This format separates the default output into two groups: virtual 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.
-S Report the number of processes swapped in and out (si and so) instead of page reclaims
and address translation faults (re and at).
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 inter-
val only. If interval is zero, the output is displayed once only. If the
-d option is
specified, the column headers are repeated. If
-d is omitted, the column headers are not
repeated.
The command
vmstat 5 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 com-
monly
ˆC and ˆ\, respectively (see stty (1)).
-f Report on the number of forks and the number of pages of virtual memory involved since
boot-up.
-s Print the total number of several kinds of paging-related events from the kernel
sum
structure that have occurred since boot-up or since vmstat was last executed with the
-z option.
-z Clear all accumulators in the kernel sum structure. This option is restricted to the super
user.
If none of these options is given,
vmstat displays a one-line summary of the virtual memory activity
since boot-up or since the -z option was last executed.
Column Descriptions
The column headings and the meaning of each column 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 considered
active if they belong to processes that are running or have run in the last 20 seconds.
avm Active virtual pages
free Size of the free list
HP-UX 11i Version 3: September 2010 − 1 − Hewlett-Packard Company 1