VMSTAT(1) GENIX Programmer's Manual VMSTAT(1)
NAME
vmstat - report virtual memory statistics
SYNOPSIS
vmstat [ -fs ] [ interval [ count ] ]
DESCRIPTION
Vmstat delves into the system and normally reports certain statis-
tics 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 argu-
ment, it instead prints the contents of the sum structure, giving
the total number of several kinds of paging related events which
have occurred since boot.
If none of these options are given, vmstat will report in a (usu-
ally) iterative fashion on the virtual memory activity in the sys-
tem. In this case, the optional interval argument causes vmstat to
report once each interval seconds; ``vmstat 5'' will print what the
system is doing every five seconds; this is a good choice of print-
ing interval since this is how often some of the statistics are sam-
pled 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 considered active if they belong to processes
which are running or have run in the last 20 seconds. A ``page''
here is 512 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.
pf page faults
pi pages paged in
po pages paged out
fo pages paged out without disk activity
zr pages zeroed during system idle loop
de anticipated short term memory shortfall
d0/d1/d2/d3: Disk operations per second on disk units 0 to 3.
Printed 11/16/83 1
VMSTAT(1) GENIX Programmer's Manual VMSTAT(1)
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
FILES
/dev/kmem, /uniximage
AUTHORS
William Joy and Ozalp Babaoglu
BUGS
There should be a screen oriented program which combines vmstat and
ps(1) in real time as well as reporting on other system activity.
Printed 11/16/83 2