vmstat

Linux · Processes · reference only

What it does

Shows system statistics: processes, memory, swap, input/output, interrupts and CPU usage.

Syntax

vmstat [opciones] [retardo [repeticiones]]

Options and parameters

• retardo repeticiones

  Seconds between samples and number of samples to take.

• -a

  Shows active and inactive memory instead of buffers and cache.

• -s

  Shows a summary of event counters and memory.

• -d

  Shows disk statistics.

• -S unidad

  Changes the memory unit: k, K, m or M.

• -t

  Adds the time to each line.

• -w

  Uses a wider format for systems with a lot of memory.

Usage examples

• vmstat

  Shows a snapshot with averages since boot.

• vmstat 1 3

  Takes three samples one second apart.

• vmstat -s

  Shows the system's memory and event counters.

• vmstat -S M 2 5

  Five samples every 2 seconds with memory in megabytes.

Notes and common mistakes

• The first line shows the average since boot; the following ones reflect the interval.
• Sustained non-zero values in the si and so columns mean the system is using swap.

Related commands

• at
• bg
• crontab
• fg
• jobs
• kill