ISC disk driver bug? (Was Disks Hang Under 2.0.2 SCSI add WD1006SRV2)

[Karl Denninger]

In article <258D393B.1670 at paris.ics.uci.edu> baxter at ics.uci.edu (Ira Baxter) writes:
>davidsen at crdos1.crd.ge.COM (Wm E Davidsen Jr) writes:
>
>>In article <258C899B.28434 at paris.ics.uci.edu> baxter at ics.uci.edu (Ira Baxter) writes:
>
>>| I use a Western Digital WD1006SRV2 (RLL 1-1 track-buffered)
>>| controller.  I (and others with 1006s) have seen identical symptoms;
>>| until I saw this thread, I assumed there was something funny about the
>>| WD1006.  I have been chasing this problem unsuccessfully even with
>>| WD's aid.  I conclude the problem is more due to the ISC drivers than
>>| the hardware.

>>  Karl Denninger posted a note on jumper settings with the 1006 which
>>could cure your problem.
>>-- 

>There are only two interesting jumpers on a WD1006 according to my WD
>documentation: W1-1,2, handling "latched" mode (unfortunately, the
>docs *don't* say what this does), and W1-5-6, which disables cache
>control.  

Turn off latched mode (install W1-1,2).

If the problem goes away, then your DRIVES can't handle it.  

If the problem does NOT go away then the problem is either (1) in the
drivers, or (2) you have a bad WD1006.  There are a lot of bad ones around;
we have had to return many of them recently.  Symptoms are exactly as
described -- random locks under heavy load.   The disk activity light is ON
solidly in these cases when it hangs.

The boards we are getting now are manufactured in a different location and
have a completely different format for the serial number.  None of these have
been bad (so far).

If the system is hanging with the activity lights OFF this is not the
problem; look to ISC in that case.

--
Karl Denninger (karl at ddsw1.MCS.COM, <well-connected>!ddsw1!karl)
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