The sar utility which is use monitor the history system performance data on your system.
To use the sar command, simply enter sar from the system,
# sar
To check the memory statistic,
# sar -r
To check the disk statistic,
# sar -d
To check network statistic,
# sar -n
To check processor statistic,
# sar -P ALL
To check certain date statistic let say 8th of the month
# sar -f /var/log/sa/sar09
