Vmstat
Encyclopedia
vmstat is a computer system monitor
ing tool that collects and displays summary information about operating system
memory, processes, interrupts, paging and block I/O
. Users of
The vmstat tool is available on most UNIX
and Unix-like
operating systems, such as FreeBSD
, Linux
or Solaris. The syntax and output of vmstat often differs slightly between different operating systems.
Example:
#> 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
#>
System monitor
A system monitor is a hardware- or software- based system used to monitor resources and performance in a computer system.Software monitors occur more commonly, sometimes as a part of a widget engine. These monitoring systems are often used to keep track of system resources, such as CPU usage and...
ing tool that collects and displays summary information about operating system
Operating system
An operating system is a set of programs that manage computer hardware resources and provide common services for application software. The operating system is the most important type of system software in a computer system...
memory, processes, interrupts, paging and block I/O
Input/output
In computing, input/output, or I/O, refers to the communication between an information processing system , and the outside world, possibly a human, or another information processing system. Inputs are the signals or data received by the system, and outputs are the signals or data sent from it...
. Users of
vmstat can specify a sampling interval which permits observing system activity in near-real time.The vmstat tool is available on most UNIX
Unix
Unix is a multitasking, multi-user computer operating system originally developed in 1969 by a group of AT&T employees at Bell Labs, including Ken Thompson, Dennis Ritchie, Brian Kernighan, Douglas McIlroy, and Joe Ossanna...
and Unix-like
Unix-like
A Unix-like operating system is one that behaves in a manner similar to a Unix system, while not necessarily conforming to or being certified to any version of the Single UNIX Specification....
operating systems, such as FreeBSD
FreeBSD
FreeBSD is a free Unix-like operating system descended from AT&T UNIX via BSD UNIX. Although for legal reasons FreeBSD cannot be called “UNIX”, as the direct descendant of BSD UNIX , FreeBSD’s internals and system APIs are UNIX-compliant...
, Linux
Linux
Linux is a Unix-like computer operating system assembled under the model of free and open source software development and distribution. The defining component of any Linux system is the Linux kernel, an operating system kernel first released October 5, 1991 by Linus Torvalds...
or Solaris. The syntax and output of vmstat often differs slightly between different operating systems.
Example:
#> 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
#>