From owner-freebsd-questions Fri Dec 21 2:48:48 2001 Delivered-To: freebsd-questions@freebsd.org Received: from freebie.xs4all.nl (freebie.xs4all.nl [213.84.32.253]) by hub.freebsd.org (Postfix) with ESMTP id A545537B41A; Fri, 21 Dec 2001 02:48:39 -0800 (PST) Received: (from wkb@localhost) by freebie.xs4all.nl (8.11.6/8.11.6) id fBLAmU623787; Fri, 21 Dec 2001 11:48:30 +0100 (CET) (envelope-from wkb) Date: Fri, 21 Dec 2001 11:48:29 +0100 From: Wilko Bulte To: Chris Wilmes Cc: damien@carroll.com, freebsd-questions@FreeBSD.ORG, freebsd-stable@FreeBSD.ORG Subject: Re: Sharing a SCSI bus with 2 controllers Message-ID: <20011221114829.E23547@freebie.xs4all.nl> References: <55670000.1008866988@50.dhcp.hck.carroll.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.2.5i In-Reply-To: ; from cwilmes@creighton.edu on Thu, Dec 20, 2001 at 05:24:52PM -0600 X-OS: FreeBSD 4.4-STABLE X-PGP: finger wilko@freebsd.org Sender: owner-freebsd-questions@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG On Thu, Dec 20, 2001 at 05:24:52PM -0600, Chris Wilmes wrote: > On Thu, 20 Dec 2001 damien@carroll.com wrote: > > > Is it possible to share a SCSI device with two different controllers? I > > have a tape backup that I want to share with two systems, and I want them > > to be both connected at the same time. I have connected both controllers to > > the tape backup, made sure that they were configured as different device > > numbers, and re-booted both systems. One is a Windows Machine, the other is > > a BSD box. Both of the controllers are the same (Adaptec 29160N) The BSD > > box is complaining about seeing SCSI bus resets on the bus: > > > > ahc0: Someone reset channel A > > > > What is the correct way to do this (if it is at all possible)? Are there > > special kernel or hardware settings required for this to work properly? > > > > > Congratulations on discovering one of the cooler features of SCSI. > > The SCSI bus resets are probably harmless, but the error messages can come > at inopportune times. You can stop most of the bus resets by changing a ^--- exactly ;-) It will still not stop the driver from issuing bus resets. Tapes on shared SCSI buses are eh, em, interesting. Imagine a bus reset from system 1 while system 2 is writing a backup. Tape rewinds, system 2 recovers and continues writing. etc. W/ -- | / o / /_ _ email: wilko@FreeBSD.org |/|/ / / /( (_) Bulte Arnhem, The Netherlands To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message