Wow, Have you looked at restoring the master, msdb, and model from tape? In an active/passive both nodes share the same physical datafiles and in an active/active the same is still true. So, It stands to reason that normal restore of master should still apply. I have looked through the resource kit,BOL, and technet and don't see any thing directly related to cluster and recovery of master. If the sql server will not start I assume you will have to run the rebuild master tool and then restore from tape. In the past we have basicly always rebuilt the cluster if the drive array went south and restored from tape. If you need more info I will try to dig some up for you.