HP DataProtector : Cannot obtain Cell Manager host

HP DataProtector : Cannot obtain Cell Manager host

Came across this one today, the below error suddenly started to appear on a SQL backup that was working one day and stopped the next without any change or modification to the SQL server or Cell Manager:

Normal 0
[Critical] From: [email protected] "OSCDB"  Time: 2/10/2011 2:40:04 AM
Cannot obtain Cell Manager host. Check the /etc/opt/omni/client/cell_server file and permissions of /etc/resolv.conf file.

On investigation I found that the CellServer registry key, listed below, was infact empty. Upon re-entering the CellServer (Cell Manager) name the backup started to work again:

HKEY_LOCAL_MACHINE\SOFTWARE\Hewlett-Packard\OpenView\OmniBackII\Site\CellServer