Understanding iostat Command and Examples in Linux

What is iostat command?

The iostat command is one of the main tools used in Linux for analyzing I/O (Input/Output) performance. This command reports a variety of information about the system’s CPU utilization and hard disk I/O including device utilization, throughput, average queue size, transfer rate and percentage of CPU time spent in servicing disk I/O.

How to use iostat command?

The syntax for using the iostat command is as follows:

iostat [-c | -d] [-t] [-h] [device list] [interval] [count]

Where:

• -c - Displays CPU statistics
• -d - Displays device statistics
• -t - Displays extended statistics
• -h - Displays help info
• device list - List of devices to gather statistics from
• interval - How often to report statistics (in seconds)
• count - Number of times to report

Examples of iostat command

Here are some examples of how to use the iostat command:

• To display CPU and device utilization statistics for all devices, run the following command:

  iostat
  

• To display extended statistics for all devices, run the following command:

  iostat -t
  

• To display statistics for device sda every 5 seconds, 3 times, run the following command:

  iostat -d sda 5 3