maj@cl.cam.ac.uk (Martyn Johnson) (08/23/89)
Since I upgraded my 3600 from Ultrix 2.2 to 3.0, I have been seeing a problem with the TK70. The sequence of events is as follows: - mt fsf to the nth file on a tape - start writing with dd, 10k blocks - during this, the message "mscp resynching - controller uq16" is written to the console and the error log - the dd completes without reporting any error - on rewinding, any attempt to read the tape fails, with the message "tms - unit 0 Record Data truncated on controller 16" written to the error log, i.e. the tape has been totally trashed. This does not happen every time, but enough to be a real nuisance. As far as I can tell the problem does not occur with TK50s on the MicroVAX-II. Field service have changed both the drive and the controller to no avail, and suggested that it is a software problem in 3.0, which sounds plausible to me. I have an open call with the Software Support Centre on this. So far they have said that they think there may be a known problem, which may be fixed in a future release. They also tried to tell me that the problem was in the tape driver, which is "not part of Ultrix but is in VMS", which decreased my confidence in them somewhat. They may have more information for me tomorrow, meanwhile the purpose of this message is to ask whether anybody else has seen this, and whether they have any firm information about where the problem lies. We have Ultrix source, and need some kernel mods, which means that upgrading from the 3.1 maintenance release tape is not an option open to me. However if somebody can give me some hints about what the problem is, I may be able to fix it myself. Martyn Johnson maj@cl.cam.ac.uk University of Cambridge Computer Lab Cambridge UK