Backing up the Master server?

Hi,

Just realised the one server I'm not backing up is the Master server itself. We run a catalog backup but not an OS backup of the Master. It is on a replicated lun but a weekly backup would probably be a good thing. 

Ours is VMWare virtual machine. Are there any recommendations for backing up the master server? Is it better to avoid backing it up/creating a snapshot when other backups are running? It doesn't perform backups itself, just does its supervisory thing, whatever that is. Backups are triggered by a 3rd party scheduling tool.  

Thanks