From: beaulieu@bose.com (Larry Beaulieu)
Subject: Re: 4/490 mysterious hangs (4.1.1)
Organization: Bose Corporation
	<STEINAR.HAUG.92Nov14175743@delab.sintef.no>
Date: Tue, 17 Nov 1992 14:01:40 GMT

In article <STEINAR.HAUG.92Nov14175743@delab.sintef.no> Steinar.Haug@delab.sintef.no (Steinar Haug) writes:

   >> We have a 64MB (memory) 4/490 with four IPI drives that we are using as
   >> a sybase engine.  It is starting to mysteriously hang more and more
   >> often and i am at a loss to explain why.  The console is a wyse
   >> terminal and there are no error messages on the console, no messages in
   >> /usr/adm/messages* and no indications of any kind anywhere else that i
   >> can think of looking that would explain why the machine just simply
   >> stopped working.  Usually there are only a few people working on it,
   >> maybe one or two running elm and news plus a couple of other smallish
   >> programs.  Of course, the sybase server is running all the time.  The
   >> times of the hangs appear random, i.e., during the day, during the
   >> night, during the weekends, etc.
   >> 
   >> Does anyone have any experience with this?  Sun could only suggest
   >> running vmstat periodically in order to try and track down memory usage
   >> at the time of the crash and also forcing a memory dump next time it
   >> crashes in order to see what routine it is in at the time of the
   >> crash.

   >We've had similar experiences with Sybase on a smaller Sun (SS-1) running
   >Sybase. Our problems disappeared after installing patch 100159-01. I have
   >included the README file below. You might also want to look into patches
   >100303-02 and 100330-06 (README for these also included).

	When I was at my previous employer we had the exact same problem, with a 
	4/470 w/32MB memory and 4 IPI drives running 4.1.1. The usual Sybase caveats
	were followed in the installation of this system (partition a not a
	raw partition, etc).  Upon a hang the system would respond to an ICMP
	echo request (ping), but would not respond to keyboard input or
	other remote requests.  This would occur anywhere from once per day	
	to about once per week.  We installed these patches and a couple of
	others, which I do not now remember.  They had no effect on the type
	or frequency of the failure.  I forget the results of our crash
	dumps, but there wasn't anything obviously funky.  Sun software support
	didn't have much to offer. Neither did Sybase.

	This system was a dedicated Sybase engine which was almost exclusively
	dedicated to local processing (few client requests) but which was
	consistently under very heavy load updating a large database.  We could 
	not replicate the problem on any of our other Sybase engines.  If
	I remember right this was under V4.2 of Sybase.

	Several times we would take a corrective step which would stop the
	problem, only to have it reappear a couple of months later. This
	included reloading the O/S, the sybase executables, and the database.

	The problem finally went away this spring when on a lark I replaced
	the IPI controller. 


	
--
Larry Beaulieu			beaulieu@bose.com
Bose Corporation		Phone: 508-879-1916 x6479
Framingham, MA 01701-9168	FAX:   508-820-4865	

		All flames gleefully ignored.