On Cpanel Server, got following error

Drive Critical: /dev/sda3 (/usr) is 91% full

This is because /usr/ partition is full, mostly disk space used by /usr/local/apache/domlogs folder.

To fix this, you can move domlogs folder in another partition that have FREE disk space.

In my cause, /backup have lot of free disk space. So, moved domlogs to /backup

service httpd stop
cd /usr/local/apache
mv domlogs /backup
ln -s /backup/domlogs
service httpd start

Now onwards, domlogs will be stored in /backup/domlogs folder.