It turns out that there’s a bug in the way VSS is handled on servers with two or more drives. On such servers, it’s possible that “Previous Versions” will be shown, but will be inaccessible or a “Cannot copy : Invalid file handle” error message will be displayed when attempting to copy or restore a previous version of a file or folder.
There’s also a loosely related bug which only affects HP and other OEM servers. Because of the way the servers are prepared for duplication, VSS is turned off when they are shipped from the factory.
On the HP MediaSmart Server VSS is turned off for all partitions.