I understand that cluster drives should be backed up using UNC path names
and the name of the virtual server. In your case you would use e.g.
\\DUNE\R$ rather than \\KRYPTON\R$ since you cannot count on the systems to
own a particular drive at any one time. This comes in at the cost of
performance because you will incur network traffic as opposed to local I/O.

A second approach would be to use a scripting tool where you could check if
any given drive is local to the system before attempting any backup
provided that NT cluster software has a command that will allow you to
check the drive status from the command line.

I will be installing ADSM on an NT cluster this month and sharing any
insight gained there. (Crossing my fingers.)

Ahmet Ertem
HAITEC GmbH
aertem AT haitec DOT de