Can you check the permissions on that disk we mounted last time I was up there? Where has that disk been mounted, please?
The disk on tumulus showed an I/O error when I attempted to change permissions on it. It was mounted as /mnt and the disk may have timed out and powered itself down and then not powered itself up quickly enough for the OS's liking.
I have remounted the disk as /gharp1 on tumulus and I made it owned by obs and group obs. I added a zero length file called gharp1 to help identify it when it is moved to a different computer. Marking this as resolved.