We have a 3 node windows 2008 R2 cluster running SQL 2008, when we failed it over to the new third node one of the drive letter of a disk changed. The disk is part of the SQL group in cluster admin but obviously once the letter change SQL could not access it as it was expecting another letter. Had to use cluster manager to change it back.
I cant see any thing in the event logs which relates to this.
Any help much appreciated.