brant@manta.pha.pa.us (Brant Cheikes) (11/28/88)
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@manta.pha.pa.us, brant@linc.cis.upenn.edu, bpa!manta!brant
thad@cup.portal.com (Thad P Floryan) (11/30/88)
Re: Brant's "random" HD errs, check your power supply's voltages. Don't laugh. I've seen UNIXpc's whose "+12VDC" was actually +10.53VDC, and the HD error symtoms are/were IDENTICAL to those you describe. There is a labelled "+12 V Adjust" potentiometer (and a +5 and -12 (unlabelled) on the UNIXpc's power supply. The easiest and most reliable way to adjust the voltage is to get one of those disk-drive power "Y" cables (probably $1 to $2) and have everything connected AND your digital VM's probes into the 3rd connector while making the adjustment Turning the +12 pot clockwise increases the voltage; be SURE to use a plastic non-conducting tool for making the adjustment (in case you sneeze and/or drop the tool into the power supply! :-) I've found that adjusting to slightly OVER the 12 volt mark is a wise move (I set mine (4 systems) to between 12.15 and 12.20 VDC) 5% of the 5VDC is 5.25V to 4.75V 5% of the 12VDC is 12.60V to 11.40V Would STRONGLY suggest doing a file backup BEFORE the voltage adjustments, esp if the adjustment alters the performance slightly (which I HAVE found to be so) Thad Floryan [thad@cup.portal.com (OR) ...!sun!portal!cup.portal.com!thad]