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From: leon@mmm.UUCP (Leon Schilmoeller)
Newsgroups: net.unix-wizards
Subject: Re: disk system hangs on a VAX-750 with SI controller.
Message-ID: <512@mmm.UUCP>
Date: Mon, 17-Feb-86 09:49:15 EST
Article-I.D.: mmm.512
Posted: Mon Feb 17 09:49:15 1986
Date-Received: Tue, 18-Feb-86 04:04:28 EST
References: <136@uwslh.UUCP>
Distribution: net
Organization: 3M Company, St. Paul, Minn.
Lines: 44

> We have a problem with our disk system hanging and need help.
> We are running a VAX-11/750 with 4.2BSD unix.
> The disk system is a Systems Industries 9900 controller with a Fujitsu
> eagle disk drive and two CDC 9730-80 disk drives (a sealed 67 M drive).
> The controller emulates a massbus device and we use the hp device driver
> that came with 4.2BSD.
> Occasionally (usually about once a month but last week as much as 5 times
> per day) the computer will hang as though a task completion interrupt from
> the disk had been lost.  Pressing the reset switch on the controller will
> cause the system to pick up running as though nothing had happened.
> Another site near us also has seen this problem.  We just installed
> a new power supply and the latest firmware in the controller, but it did
> not help.  SI suggested using their version of the hp driver, but
> (a) did not think it would help and (b) I don't see anything in their changes
> that appears to address this problem.
> Does anyone know what is going on and what we can do about the problem?
> 1.  Is it hardware (and if so has anyone identified it well enough for
>     SI to fix it)?
> 2.  Is it software and if so can someone point me to a fix.
> 3.  I have considered going into the hp driver and modifying it so that
>     there is a timeout on pending disk activity (or maybe use the system
>     lightning bolt) so that if we wait over one second for a disk interrupt
>     we will consider the disk drive to be hung and issue a reset.
>     Has anyone tried this and will you send me the code if you have.
>     Or when it hangs does the controller become so stuck that a software
>     issued reset is ignored and we have to hit the switch.
> Any help on this will be appreciated.
> -- 
> David E. Miran         ...!{seismo,harvard,topaz,ihnp4}!uwvax!uwslh!dem
> Wisconsin State Hygiene Lab          (608) 262-0019
> University of Wisconsin
> 465 Henry Mall
> Madison, WI  53706

We have experienced the same problem with the si9900 on a VAX 11/780.  We
have 3 eagles and a 9766 on the one controller.  Using the hp driver from
SI does not make any difference, at least not for us.  It has been
some time since a reset has been needed on my system, but as you have
indicated, there appears to be no real pattern.  Sorry I do not have a
fix, but just wanted to let you know it is not only a 750 problem.

Leon Schilmoeller			ihnp4!mmm!leon
3M					612-736-9653
St. Paul, MN 55144