> From owner-port-pmax@NetBSD.ORG Mon Nov  7 08:27:57 1994
> Message-Id: <199411071554.IAA09462@sidney.novatel.ca>
> X-Authentication-Warning: sidney.novatel.ca: Host localhost.novatel.ca didn't use HELO protocol
> To: Ted Spradley <tsprad@metronet.com>
> Cc: port-pmax@NetBSD.ORG
> Subject: Re: System hangs with the disk light on 
> From: Herb Peyerl <hpeyerl@novatel.ca>
> Date: Mon, 07 Nov 1994 08:54:51 -0700
> Sender: owner-port-pmax@NetBSD.ORG
> Precedence: list
> 
> On Mon, 7 Nov 1994 00:20:57 -0600 (CST)   Ted Spradley <tsprad@metronet.com> wrote:
>  > If no one else has seen this I'll look for hardware bugs (questionable
>  > cabling to second disk), if others have the same symptoms I'll look for
>  > device driver bugs, unless anyone has a better suggestion.
> 
> Haven't seen it... Mines been up 3 days so far.

I have seen this on 4.4 systems. It usually has to do with old disk drives
(like the RZ23) that can't handle large SCSI transfers. Try
	sysctl -w debug.doclusterread=0
	sysctl -w debug.doclusterwrite=0
to disable clustered disk I/O. It could also be a bug in the sii driver
but without a SCSI logic analyzer, I couldn't find it.

      -m-------  Ralph Campbell				ralphc@pyramid.com
    ---mmm-----  Pyramid Technology Corporation		Tel: (408) 428-8639
  -----mmmmm---  3860 North First Street M.S. SJ2-2-30	Fax: (408) 428-8845
-------mmmmmmm-  San Jose, CA 95134