I have just built my VCB proxy and done a few test backups. Its working great. I noticed one issue though. If I go into disk management on the VCB proxy windows box, I can see all my ESX Luns. It even lets me delete the partitions and kill my VMFS if I want. I think this is a disaster waiting to happen. Any way to lock these down so that the VCB proxy can only read the data off the luns, but not whack the partitions? I am guessing I will just have to not allow anyone to log into the VCB server if there isn't a fix.
What is your storage being used. There is normally an option with the storage management to mount lun's as read-only which would do it for you.
I have also taken system and any other accounts off of dmadmin.exe and added in a local admin account to the permissions.
This way only this local admin account can go in to disk admin... I tried GPO but there was a way around it each time.