Monitoring CPU usage is a crucial aspect of system administration as it provides insights into the performance and resource utilization of a system. On AIX, there are several methods to check CPU usage, each offering varying levels of detail and functionality.
One of the most commonly used commands is “sar”, which provides a continuous display of system activity. By default, sar reports CPU usage in 10-second intervals, but this can be customized using the “-i” option to specify a different interval. The output of sar includes columns for %user, %system, %idle, and %wait, which represent the percentage of time the CPU is spent in user mode, system mode, idle, and waiting for I/O, respectively.