From owner-freebsd-scsi Mon Feb 7 13:38: 9 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 86D3D40C8 for ; Mon, 7 Feb 2000 13:38:04 -0800 (PST) Received: (from ken@localhost) by panzer.kdm.org (8.9.3/8.9.1) id OAA24242; Mon, 7 Feb 2000 14:38:33 -0700 (MST) (envelope-from ken) Date: Mon, 7 Feb 2000 14:38:33 -0700 From: "Kenneth D. Merry" To: Gerard Roudier Cc: Wilko Bulte , George Morgan , freebsd-scsi@FreeBSD.ORG Subject: Re: Rescan for Devices... Message-ID: <20000207143833.A24212@panzer.kdm.org> References: <20000207191037.A386@yedi.iaf.nl> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Mailer: Mutt 1.0i In-Reply-To: ; from groudier@club-internet.fr on Mon, Feb 07, 2000 at 10:55:33PM +0100 Sender: owner-freebsd-scsi@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org On Mon, Feb 07, 2000 at 22:55:33 +0100, Gerard Roudier wrote: > On Mon, 7 Feb 2000, Wilko Bulte wrote: > > On Mon, Feb 07, 2000 at 10:12:57AM -0500, George Morgan wrote: > > > Is there a way to use the *BSD command "scsi" to rescan for > > > devices on a scsi controller? I'm actually trying to do this on an > > > OpenBSD 2.6 (sparc) machine, but I know there are some people > > > that really know SCSI well on this list... > > > > man camcontrol > > > > and then: > > > > camcontrol rescan > > > > Works just fine. > > Not really for me, may-be since I donnot want to rescan the bus, but to > just scan the bus for devices that haven't been seen by CAM at boot for > some reason. > > First attempt after having switched the box on and booted for the first > time: > > at scbus1 target 0 lun 0 (da3,pass4) > at scbus1 target 1 lun 0 (da2,pass3) > at scbus1 target 4 lun 0 (da5,pass6) > at scbus1 target 5 lun 0 (da4,pass5) > > Second attempt after having rebooted the machine: > > at scbus1 target 0 lun 0 (da4,pass5) > at scbus1 target 1 lun 0 (da3,pass4) > at scbus1 target 4 lun 0 (da2,pass3) > at scbus1 target 5 lun 0 (da5,pass6) > > Problem is that the order of da# devices after first boot + scanbus 1 is > different from order after second boot + scanbus 1. Which devices appear during the boot, and which ones appear after the rescan? It seems rather odd to me that your disks aren't showing up at boot. Are they not powered on or something? > 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. Ken -- Kenneth Merry ken@kdm.org To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-scsi" in the body of the message