From owner-freebsd-scsi Mon Feb 7 13:47:51 2000 Delivered-To: freebsd-scsi@freebsd.org Received: from panzer.kdm.org (panzer.kdm.org [216.160.178.169]) by builder.freebsd.org (Postfix) with ESMTP id 789623FE8 for ; Mon, 7 Feb 2000 13:47:41 -0800 (PST) Received: (from ken@localhost) by panzer.kdm.org (8.9.3/8.9.1) id OAA24385; Mon, 7 Feb 2000 14:48:04 -0700 (MST) (envelope-from ken) Date: Mon, 7 Feb 2000 14:48:04 -0700 From: "Kenneth D. Merry" To: Gerard Roudier Cc: Wilko Bulte , George Morgan , freebsd-scsi@FreeBSD.ORG Subject: Re: Rescan for Devices... Message-ID: <20000207144804.A24368@panzer.kdm.org> References: <20000207191037.A386@yedi.iaf.nl> <20000207143833.A24212@panzer.kdm.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Mailer: Mutt 1.0i In-Reply-To: <20000207143833.A24212@panzer.kdm.org>; from ken@kdm.org on Mon, Feb 07, 2000 at 02:38:33PM -0700 Sender: owner-freebsd-scsi@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org On Mon, Feb 07, 2000 at 14:38:33 -0700, Kenneth D. Merry wrote: > On Mon, Feb 07, 2000 at 22:55:33 +0100, Gerard Roudier wrote: > > I guess the reasons given that xpt_scan_bus() is scanning targets > > (excepted the initiator obviously) in parallel. I would think that such a > > concurrent target scanning can be faster than a sequential scanning, only > > if some devices, that are too long for responding to SCSI commands used > > for the probe, (probably INQUIRY) disconnect the BUS during the scan. But > > if this happens, or if some devices are reporting transient problems, then > > order of devices cannot be guaranteed on successive (reboots) + (re)scan > > of BUS. > > > > In my opinion, an option that will allow to request a sequential BUS > > (re)scan would be useful, not only for me. > > Devices are attached sequentially, unless you hard-wire them. If you > rescan the bus, though, the disks are given the first available device > number. > > If you want things to turn up in the same place every time, I would suggest > hardwiring your disk device numbers to a specific bus/target/lun. BTW, devices not probing in sequential order during a rescan is a known bug. You might want to file a PR, and then assign it to Justin. (He said it's on his list of things to fix.) Hardwiring should work around the problem, however. Hardwiring might be broken in -current, though, some people on the current list are complaining about it. Ken -- Kenneth Merry ken@kdm.org To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-scsi" in the body of the message