Collect, report or save system activity information with sar


sar is another powerful, versatile system. It is a sort of a jack o’ all trades when it comes to monitoring and logging system activity. sar can be very useful for trying to analyze strange system problems where normal logs like boot.msg, messages or secure under /var/log do not yield too much information.
sar writes the daily statistics into log files under /var/log/sa.
Like we did before, we can monitor CPU utilization (every 2 seconds, 10 times):
sar -u 2 10
CPU example
Or you may want to monitor disk activity (10 iterations, every 5 seconds):
sar -d 5 10
Disk example
Now for some really cool stuff …