From owner-freebsd-stable@FreeBSD.ORG Wed Apr 27 12:57:41 2011 Return-Path: Delivered-To: freebsd-stable@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 84ACC1065675 for ; Wed, 27 Apr 2011 12:57:41 +0000 (UTC) (envelope-from jdc@koitsu.dyndns.org) Received: from qmta15.westchester.pa.mail.comcast.net (qmta15.westchester.pa.mail.comcast.net [76.96.59.228]) by mx1.freebsd.org (Postfix) with ESMTP id 2EFE38FC0A for ; Wed, 27 Apr 2011 12:57:40 +0000 (UTC) Received: from omta18.westchester.pa.mail.comcast.net ([76.96.62.90]) by qmta15.westchester.pa.mail.comcast.net with comcast id ccjP1g0031wpRvQ5Fcxh7s; Wed, 27 Apr 2011 12:57:41 +0000 Received: from koitsu.dyndns.org ([67.180.84.87]) by omta18.westchester.pa.mail.comcast.net with comcast id ccxe1g00Z1t3BNj3ecxeq3; Wed, 27 Apr 2011 12:57:40 +0000 Received: by icarus.home.lan (Postfix, from userid 1000) id D677B9B418; Wed, 27 Apr 2011 05:57:36 -0700 (PDT) Date: Wed, 27 Apr 2011 05:57:36 -0700 From: Jeremy Chadwick To: Denny Schierz Message-ID: <20110427125736.GA1977@icarus.home.lan> References: <1303906834.4232.91.camel@pcdenny> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1303906834.4232.91.camel@pcdenny> User-Agent: Mutt/1.5.21 (2010-09-15) Cc: freebsd-stable Subject: Re: MPS driver: force bus rescan after remove SAS cable X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 27 Apr 2011 12:57:41 -0000 On Wed, Apr 27, 2011 at 02:20:34PM +0200, Denny Schierz wrote: > hi, > > if I remove the SAS cable from the JBOD (connected through a SAS > switch), all disks disappears, that's fine and expected, but if I > reconnect the cable, the disks are not added anymore. > I've red to use "camcontrol rescan all", but nothing happens. I don't > get my /dev/da0-47 devices anymore and have to reboot the whole machine. > > What is my mistake? Does resetting the bus then rescanning improve things at all? E.g. for bus 0 (use "all" only if it's safe): camcontrol reset 0 camcontrol rescan 0 I'm doubting it will. This is the first time I've heard of something called a SAS switch (looks like a SAS expander to me), but searching the Web indicates that most of these devices have a form of firmware/administrative interface on them, which means it's highly likely that the device itself is "getting in the way". Meaning: what's to say the issue is with FreeBSD and not with the SAS switch? To me, my first choice of action would be to contact the device vendor and ask what the behaviour should be. If there's some sort of device with an ASIC in between your disks and the controller (which is the case here), that could be responsible for what you're seeing. Or, if the hot-swap backplane has something like SES (not a typo) or a QLogic GEM chip on it, that could be causing some issues. (In the case of the latter on our SCSI systems at work, we change the physical SCSI cabling in our systems to remove the GEM from the bus entirely, otherwise it does odd things like tries to renumber the SCSI IDs on devices during a failure, and more often than not locks the entire SCSI controller up). Bottom line: less actual stuff between the disk and the controller the better. :-) -- | Jeremy Chadwick jdc@parodius.com | | Parodius Networking http://www.parodius.com/ | | UNIX Systems Administrator Mountain View, CA, USA | | Making life hard for others since 1977. PGP 4BD6C0CB |