Sep 11th, 2009
The iostat command
The iostat command
The iostat command at its most basic provides an overview of CPU and disk I/O statistics:
Linux 2.6.27-1-i686-dream (buddies) 09/11/09 _i686_ (1 CPU)
avg-cpu: %user %nice %system %iowait %steal %idle
12.97 0.00 3.60 5.57 0.00 77.86
Device: tps Blk_read/s Blk_wrtn/s Blk_read Blk_wrtn
sda 15.46 284.99 170.77 620297 371696
Below the first line (which contains the system’s kernel version and hostname, along with the current date), iostat displays an overview of the system’s average CPU utilization since the last reboot.
The CPU utilization report includes the following percentages:
Percentage of time spent in user mode (running applications, etc.)
Percentage of time spent in user mode (for processes that have altered their scheduling priority using nice(2))
Percentage of time spent in kernel mode.
Percentage of time spent idle.
Below the CPU utilization report is the device utilization report. This report contains one line for each active disk device on the system.
