Vmstat

{{Infobox Software | name = vmstat | logo = | screenshot = | screenshot size = | caption = | author = | developer = AT&T Bell Laboratories | released = {{Start date and age|1985|2}} | latest release version = | latest release date = | operating system = Unix and Unix-like | genre = Command | license = | website = }} '''vmstat''' ('''''v'''irtual '''m'''emory '''stat'''istics'') is a computer system monitoring tool that collects and displays summary information about operating system memory, processes, interrupts, paging and block I/O. Users of <code>vmstat</code> can specify a sampling interval which permits observing system activity in near-real time.<ref>{{Cite report | last1 = Chatterjee | first1 = Pooja | last2 = Mukherjee | first2 = Rohit | last3 = Das | first3 = Ishita | last4 = Roy | first4 = Tanmay | year = 2021 | title = Real-time performance benchmarking using vmstat/iostat | url = https://www.researchgate.net/publication/393509597_REAL-TIME_PERFORMANCE_BENCHMARKING_USING_VMSTATIOSTAT | accessdate = 2026-03-22 }}</ref>

The vmstat tool is available on most Unix and Unix-like operating systems, such as FreeBSD, Linux or Solaris.

==Syntax== The syntax and output of vmstat often differs slightly between different operating systems.

<syntaxhighlight lang="console"> # vmstat 2 6 procs -----------memory---------- ---swap-- -----io---- --system-- ----cpu---- r b swpd free buff cache si so bi bo in cs us sy id wa 0 0 2536 21496 185684 1353000 0 0 0 14 1 2 0 0 100 0 0 0 2536 21496 185684 1353000 0 0 0 28 1030 145 0 0 100 0 0 0 2536 21496 185684 1353000 0 0 0 0 1026 132 0 0 100 0 0 0 2536 21520 185684 1353000 0 0 0 0 1033 186 1 0 99 0 0 0 2536 21520 185684 1353000 0 0 0 0 1024 141 0 0 100 0 0 0 2536 21584 185684 1353000 0 0 0 0 1025 131 0 0 100 0 </syntaxhighlight>

In the above example the tool reports every two seconds for six iterations.

We can get the customized or required outputs by using various options with the vmstat command.

;<syntaxhighlight lang="console" inline># vmstat –s</syntaxhighlight>: This option is used to get ''memory statistics''.

;<syntaxhighlight lang="console" inline># vmstat –d</syntaxhighlight>: This option is used to get ''disk statistics''.

== See also == * nmon — a system monitor tool for the AIX and Linux operating systems. * iostat * top * sar

==References== {{reflist}}

== External links == * {{man|8|vmstat|FreeBSD}} * {{man|8|vmstat|Solaris}} * {{man|8|vmstat|die.net|Report virtual memory statistics}} * [http://www.softpanorama.org/Utilities/vmstat.shtml Softpanorama vmstat page]

Category:Unix software Category:System monitors