Managing System Performance
The system administrator should monitor system performance to see if any bottlenecks or other system problems are developing. Several system utilities are useful in this regard.
System Activity Reports
The sar command is a very powerful way to look at various aspects of system performance. Run this from the root account. The following is the general syntax of sar:
sar -REPORT LEN CNT
The following are your available options:
REPORT is a single-letter option to tell what report to run. Here are three of the most useful reports:
-u reports CPU usage.
-b reports disk buffer and cache access.
-d reports disk drive usage.
There are many more reports as well. Check the man page on sar.
LEN tells how long to monitor the system ...