Below is the error that I receive :
Solution :root@server [~]# sar -q
Cannot open /var/log/sa/sa08: No such file or directory
root@server [~]#
Most probably its because of the cron.
First check if service cron is running.
If not restart that/etc/init.d/crond status
/etc/init.d/crond restart
/etc/init.d/syslog restart