1. Install SysStat
apt-get install sysstat

2. Enable Stat collection
Open vi /etc/default/sysstat
Edit the file, change “ENABLED” to “true”.

3. Start Sysstat
/etc/init.d/sysstat start

3.a. By default, sysstat reports activity every 10 minutes everyday.
If you’d like to change that interval, edit it here:
/etc/cron.d/sysstat

4. To look at your load averages, type in
sar -A