OSF

NAME

vmstat − Shows Mach virtual memory statistics

SYNOPSIS

vmstat interval [count]

vmstat [-f | -s]

The vmstat command displays statistics kept about virtual memory, processes, trap, and CPU activity. 

FLAGS

-fDisplays only statistics about the number of forks since system startup (see the fork() call). 

-sDisplays accumulated statistics along with the page size. 

DESCRIPTION

If you specify interval, vmstat displays the statistics listed below every interval seconds.  The first report is for all time since a reboot, and each subsequent report is for the last interval only.  If you specifty count after interval, count specifies the number of reports.  For example, vmstat 1 10 produces 10 reports at 1-second intervals.  You cannot specify count without interval, since the first numeric argument to vmstat is always assumed to be interval. 

The following values are displayed:

Process information:

rNumber of threads

wNumber of threads waiting interruptibly

uNumber of threads waiting uninterruptibly

Virtual memory information:

actTotal number of pages currently in use and pageable

freeTotal number of free pages in the system

wiredTotal number of pages wired down

faultsNumber of address translation faults that have occurred

cowNumber of copy on write page faults

zeroNumber of zero fill page faults

reactNumber of pages that have been faulted while on the inactive list

pinNumber of requests for pages from a pager

poutNumber of pages that have been paged out

Interrupt information:

inNumber of non-clock device interupts per second

syNumber of system calls called per second

csNumber of task and thread context switches per second

CPU information:

usPercentage of user time for normal and priority processes

syPercentage of system time

idPercentage of idle time

Specify -f to display fork statistics only.  Specify -s for a single display of accumulated statistics, as well as page size. 

RELATED INFORMATION

Commands:  iostat(1). 

Functions:  table(2), vm_statistics(2).