Skip site navigation (1)Skip section navigation (2)
Date:      Fri, 26 May 1995 08:21:33 -0400 (EDT)
From:      Peter Dufault <dufault@hda.com>
To:        davidg@Root.COM
Cc:        hsu@cs.hut.fi, freebsd-bugs@freefall.cdrom.com
Subject:   Re: MAJOR problem with FreeBSD-2.0-RELEASE
Message-ID:  <199505261221.IAA05683@hda.com>
In-Reply-To: <199505260214.TAA00145@corbin.Root.COM> from "David Greenman" at May 25, 95 07:14:27 pm

next in thread | previous in thread | raw e-mail | index | archive | help
David Greenman writes:
> 
> >all accesses to the disk which first generated an error fail.  Everything
> >around the disks, including cables have been changed several times, so it
> >is either the disks or the software.
> 
>    Probably both. One of the drives is hanging the SCSI bus, and FreeBSD
> doesn't cope with it correctly. I've seen this happen myself...

Properly resetting the SCSI bus, the host adapter, renegotiating
sync transfers, waiting for all devices to come ready again and
getting their "bus device reset occurred" message, reaping all
outstanding I/O transactions, and then retrying those outstanding
transactions is an effort that includes modifying all the host
adapter drivers (and looking for a common interface to pull up out of
them) and so will be a tough job to adequately test.  It should
also be done in conjunction with better I/O transaction scheduling
to cleanly support tag queuing. This is a 2.1 adventure.

-- 
Peter Dufault               Real Time Machine Control and Simulation
HD Associates, Inc.         Voice: 508 433 6936
dufault@hda.com             Fax:   508 433 5267



Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?199505261221.IAA05683>