sar — System Activity Report
The sar command writes to standard output the contents of selected cumulative activity counters in the operating system. The accounting system, based on the values in the count and interval parameters, writes information the specified number of times spaced at the specified intervals in seconds.
$ sar — Print the CPU Utilization report.
$ sar -A — Print all info in report format.
$ sar -b — Report I/O and transfer rate statistics.
$ sar -e 12:00:00 — Print report from 00Hr to 12Hr
$ sar -s 10:30:00 — Print report from 10:30AM to now.
$ sar -u 2 5 -o out.file — Report CPU utilization for each 2 seconds & write the 5 lines output to out.file.
$ sar -f out.file — Generate the report from the out.file.
$ sar -h -f out.file — Print file contents in a format that can easily be handled by pattern processing commands (ex: awk)
$ sar -r -n DEV -f /var/log/sa/sa01 — Display memory, swap & network statistics saved in daily log file ‘sa01’.
$ sar -R 2 5 — Report memory statistics for each 2Sec for 5times.
Read: man sar