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From: alen@cogen.UUCP (Alen Shapiro)
Newsgroups: comp.unix.wizards
Subject: Re: SI 9900 hangs
Message-ID: <331@cogen.UUCP>
Date: Tue, 18-Aug-87 13:02:30 EDT
Article-I.D.: cogen.331
Posted: Tue Aug 18 13:02:30 1987
Date-Received: Fri, 21-Aug-87 02:35:45 EDT
References: <8269@brl-adm.ARPA> <3321@cit-vax.Caltech.Edu> <654@stracs.cs.strath.ac.uk>
Reply-To: alen@cogen.UUCP (Alen Shapiro)
Organization: Cogensys, LaJolla, Calf.
Lines: 35

In article <654@stracs.cs.strath.ac.uk> jim@cs.strath.ac.uk writes:
>In article <3321@cit-vax.Caltech.Edu> mangler@cit-vax.Caltech.Edu (System Mangler) writes:
>>In article <8269@brl-adm.ARPA>, eichelbe@nadc.arpa (J. Eichelberger) writes:
>>> Every so often we get a system hang.	All activity on the SI controller
>>> stops.  Hitting the reset on the toggle switch restarts everything.  Most
>>> of the time we don't see any error messages.	If we do see one, it's
>>> hp0: not ready
>>
>>The SI local office says this is a common problem, typically caused
>>by marginal power supply output.  I've not had the chance to verify
>>this (there isn't enough downtime on this machine for my purposes).
>
>We had this problem quite often just after we installed a 9900. The
>SI engineer tweaked the voltage on the 9900 power supply and the hangs
>stopped happening. Eighteen months later, we've had no repetitions.
> .......etc.....

At Turing Institute Glasgow we had 2 Vax 750s and 2 SI9900s. We frequently
(couple of times a month) had the aforementioned problem. Without fail, hitting
the reset button worked. We had our mains monitored and the hangs corresponded
with voltage spikes/dropouts not severe enough to take down our
750s but bad enough to cause the 9900s to act like Rip-Van-Winkle
(our pdp11/24 frequently didn't survive though).

I seem to remember SI installed a driver fix that could detect when the problem
occured and did an off-spindle* seek to reset the drive.

Is anyone at TI or SI listening? colin@tivax do you remember this?

*off-spindle seek = seek till you hit the end-stop

ps Hi Jim

--alen the lisa slayer (it's a long story)
	...!seismo!esosun!cogen!alen