3600 disk drive problem

[Tom.Wood@FAS.RI.CMU.EDU]

   I've got a drive (an Eagle) on a 3600 that is misbehaving.  Every
now and then a disk operation fails (usually a DISK-SEARCH-ERROR or
device not mounted).  Every time this happens it is possible to drop
into the FEP, type "Show Disk Label 1" (the drive is unit 1) and be
rewarded with "Wrong pkid read from header."  (Actually, any FEP
command that touches the disk produces this message.)  Sometimes the
problem goes a way by itself--sometimes setting the disk type tickles
something and the problem disappears.

   Question:  I have been unable to find out what the message "Wrong
pkid read from header" really means.  Consequently I am not sure
exactly where the problem lies.  Anybody seen this one before?

   Thanks much.

			      -Tom Wood
			       taw@fas.ri.cmu.edu