vmstat | HP-UX 11i Systems Administration Handbook and Toolkit (2nd Edition)

vmstat - graphics/vmstart_icon.gif Report process, virtual memory, trap, and CPU activity.

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. -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. 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 commonly ^C and ^\, 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 requires write file access permission on /dev/kmem. This is normally restricted to users with appropriate privileges. 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 page Information about page faults and paging activity. These are averaged each five seconds, and given in units per second. re Page reclaims (without -S) at Address translation faults (without -S) si Processes swapped in (with -S) so Processes swapped out (with -S) 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 faults Trap/interrupt rate averages per second over last 5 seconds. in Device interrupts per second (nonclock) 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 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. vmstat procs memory page faults cpu r b w avm free re at pi po fr de sr in sy cs us sy id 0 0 0 1158 511 0 0 0 0 0 0 0 111 18 7 0 0 100 2. Add the disk tranfer information to the default output. vmstat -d procs memory page faults cpu r b w avm free re at pi po fr de sr in sy cs us sy id 0 0 0 1158 511 0 0 0 0 0 0 0 111 18 7 0 0 100 Disk Transfers device xfer/sec c0t6d0 0 c0t1d0 0 c0t3d0 0 c0t5d0 0 3. Display the default output in 80-column format. vmstat -n VM memory page faults avm free re at pi po fr de sr in sy cs 1158 430 0 0 0 0 0 0 0 111 18 7 CPU cpu procs us sy id r b w 0 0 100 0 0 0 4. Replace the page reclaims and address translation faults with process swapping in the default output. vmstat -S procs memory page faults cpu r b w avm free si so pi po fr de sr in sy cs us sy id 0 0 0 1158 430 0 0 0 0 0 0 0 111 18 7 0 0 100 5. Display the default output twice at five-second intervals. Note that the headers are not repeated. vmstat 5 2 procs memory page faults cpu r b w avm free re at pi po fr de sr in sy cs us sy id 0 0 0 1158 456 0 0 0 0 0 0 0 111 18 7 0 0 100 0 0 0 1221 436 5 0 5 0 0 0 0 108 65 18 0 1 99 6. Display the default output twice in 80-column format at five- second intervals. Note that the headers are not repeated. vmstat -n 5 2 VM memory page faults avm free re at pi po fr de sr in sy cs 1221 436 0 0 0 0 0 0 0 111 18 7 CPU cpu procs us sy id r b w 0 0 100 0 0 0 1221 435 2 0 2 0 0 0 0 109 35 17 0 1 99 0 0 0 7. Display the default output and disk transfers twice in 80-column format at five-second intervals. Note that the headers are repeated. vmstat -dn 5 2 VM memory page faults avm free re at pi po fr de sr in sy cs 1221 435 0 0 0 0 0 0 0 111 18 7 CPU cpu procs us sy id r b w 0 0 100 0 0 0 Disk Transfers device xfer/sec c0t6d0 0 c0t1d0 0 c0t3d0 0 c0t5d0 0 VM memory page faults avm free re at pi po fr de sr in sy cs 1219 425 0 0 0 0 0 0 0 111 54 15 CPU cpu procs us sy id r b w 1 8 92 0 0 0 Disk Transfers device xfer/sec c0t6d0 0 c0t1d0 0 c0t3d0 0 c0t5d0 0 8. Display the number of forks and pages of virtual memory since boot-up. vmstat -f 24558 forks, 1471595 pages, average= 59.92 9. Display the counts of paging-related events. vmstat -s 0 swap ins 0 swap outs 0 pages swapped in 0 pages swapped out 1344563 total address trans. faults taken 542093 page ins 2185 page outs 602573 pages paged in 4346 pages paged out 482343 reclaims from free list 504621 total page reclaims 124 intransit blocking page faults 1460755 zero fill pages created 404137 zero fill page faults 366022 executable fill pages created 71578 executable fill page faults 0 swap text pages found in free list 162043 inode text pages found in free list 196 revolutions of the clock hand 45732 pages scanned for page out 4859 pages freed by the clock daemon 36680636 cpu context switches 1497746186 device interrupts 1835626 traps 87434493 system calls WARNINGS Users of vmstat 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 vmstat was developed by the University of California, Berkeley and HP. FILES /dev/kmem SEE ALSO iostat(1).