how to use iostat command with its examples

• About iostat : Report CPU statistics and input/output statistics for devices
• It comes from “sysstat-9.0.4” package.
• Configuration Files:
         /proc/stat – It contains system statistics.
         /proc/uptime – It contains system uptime.
         /proc/partitions – It contains disk statistics (for pre 2.5 kernels that have been patched).
         /proc/diskstats – It contains disks statistics (for post 2.5 kernels).
         /sys – It contains statistics for block devices (post 2.5 kernels).
         /proc/self/mountstats – It contains statistics for network filesystems.

iostat generates three types of reports,

• CPU Utilization report
• Device Utilization report
• Network File system report.

Examples:

To get the CPU utilization

$ iostat -c $ iostat -c 2 10         (With delay of 2 seconds and 10 iterations)

 To get the device utilization

$ iostat -d $ iostat -d 2 10         (With delay of 2 seconds and 10 iterations)

 To display the human readable NFS IO stats

$ iostat -nh $ iostat -n -h 2 10         (With delay of 2 seconds and 10 iterations)

To display the stats in kilo bytes instead of bytes/second

$ iostat -k  $ iostat -k 2 10         (With delay of 2 seconds and 10 iterations)

To display the stats in mega bytes instead of bytes/second

$ iostat -m  $ iostat -m 2 10         (With delay of 2 seconds and 10 iterations)

To display the registered device mapper names

$ iostat -N  $ iostat -N 2 10         (With delay of 2 seconds and 10 iterations)

To display the NFS reports

$ iostat -n  $ iostat -n 2 10         (With delay of 2 seconds and 10 iterations)

To display the stats for block devices and their partitions

$ iostat -p  $ iostat -p 2 10         (With delay of 2 seconds and 10 iterations)

 To get the time for each report displayed

$ iostat -t  $ iostat -t 2 10         (With delay of 2 seconds and 10 iterations)

To get the version number

$ iostat -V  $ iostat -V 2 10         (With delay of 2 seconds and 10 iterations)

To display the extended statistics

$ iostat -x $ iostat -x sda $ iostat -x sda 2 5         (With delay of 2 seconds and 10 iterations)

To tell iostat to omit the output

$ iostat -z  $ iostat -z 2 10         (With delay of 2 seconds and 10 iterations)

Related Commands: sar, pidstat, mpstat, vmstat