Random HDERRs

[Brant Cheikes]

Hmph.  A brand-spanking-new Seagate ST-4096 and now for the first time
I'm starting to see random HDERRs logged to /usr/adm/unix.log.  Here's
a sampling:

HDERR ST:51 EF:10 CL:FFAA CH:FF00 SN:FF08 SC:FF02 SDH:FF26 DMACNT:FFFF
DCRREG:96 MCRREG:9F00 Wed Nov 23 00:54:12 1988

HDERR ST:51 EF:10 CL:FFAA CH:FF00 SN:FF06 SC:FF04 SDH:FF27 DMACNT:FFFF
DCRREG:97 MCRREG:9300 Fri Nov 25 08:04:31 1988

HDERR ST:51 EF:10 CL:FF9D CH:FF00 SN:FF06 SC:FF02 SDH:FF23 DMACNT:FFFF
DCRREG:93 MCRREG:9B00 Sat Nov 26 05:31:06 1988

HDERR ST:51 EF:10 CL:FFAD CH:FF00 SN:FF0C SC:FF02 SDH:FF21 DMACNT:FFFF
DCRREG:91 MCRREG:D500 Sun Nov 27 17:21:06 1988

HDERR ST:51 EF:10 CL:FFB4 CH:FF02 SN:FF0C SC:FF04 SDH:FF22 DMACNT:FFFF
DCRREG:92 MCRREG:9B00 Sun Nov 27 17:29:17 1988

HDERR ST:51 EF:10 CL:FFA1 CH:FF00 SN:FF00 SC:FF02 SDH:FF22 DMACNT:FFFF
DCRREG:92 MCRREG:DD00 Sun Nov 27 17:35:09 1988

I only get lines like these in my log.  I know how to read CL, CH, SN,
SC, and SDH (and the date :-); the others are a mystery.  Diagnostics
don't pick up any bad blocks that aren't already in the bad block
table.  And the errors seem to be too randomly spread over the disk to
be bad blocks.

Today I was doing lots of compiling, and lots of errors got logged.
I didn't lose anything, and the system didn't hang or crash.  But I
definitely heard an unusual noise from the disk each time an error got
logged.

Any ideas as to what might be wrong?  Is the disk defective?
-- 
Brant Cheikes
University of Pennsylvania
Department of Computer and Information Science
brant at manta.pha.pa.us, brant at linc.cis.upenn.edu, bpa!manta!brant