How to diagnose high loads with the "iostat" command

Question

How do you diagnose high loads with the iostat command?

Note: The iostat command does not work on OpenVZ/Virtuozzo containers.

Answer

1. Access the server's command line as the 'root' user via SSH or Terminal in WHM.

2. Run the following command:

   # iostat -hx  $interval $count

   Note: "$interval" and "$count" must be replaced with the polling interval in seconds and the polling count. 
   For example, an $interval of 2, and a $count of 5. Will Perform a check 5 times, with 2 seconds between checks.

Additional Resources

What is IOWait relative to the sar command, and when should I be concerned?

How to diagnose high loads with "sar" command

How to diagnose high load with the "ps" command

How to diagnose high I/O and high load with iotop