How to fix locked backup partition
There is a known incompatibility when cPanel runs on CloudLinux under Centos 5.X. After a nightly backup runs or a restore runs, the backup partition will get stuck in an active lock. The next time you perform a backup or a restore, you will see an error similar to the following:
[backupmount] Cannot umount: /backup. This mountpoint is still in use and has an active lock mount: /dev/sdc1 already mounted or /backup busymount: according to mtab, /dev/sdc1 is already mounted on /backup
Then check Backup partition is locked and will not unmount
In order to resolve this, you will need to perform the following commands as root
mount -r /backup mount -o remount,rw /backup umount /backup
Thats all..
