From owner-freebsd-stable@FreeBSD.ORG Thu Aug 16 17:08:17 2007 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 DFFC216A417 for ; Thu, 16 Aug 2007 17:08:17 +0000 (UTC) (envelope-from jdc@parodius.com) Received: from mx01.sc1.parodius.com (mx01.sc1.parodius.com [72.20.106.3]) by mx1.freebsd.org (Postfix) with ESMTP id C9E9C13C45E for ; Thu, 16 Aug 2007 17:08:17 +0000 (UTC) (envelope-from jdc@parodius.com) Received: by mx01.sc1.parodius.com (Postfix, from userid 1000) id BF7441CC069; Thu, 16 Aug 2007 10:08:17 -0700 (PDT) Date: Thu, 16 Aug 2007 10:08:17 -0700 From: Jeremy Chadwick To: Kevin Oberman Message-ID: <20070816170817.GA20470@eos.sc1.parodius.com> Mail-Followup-To: Kevin Oberman , Eugene Grosbein , Artem Kuchin , freebsd-stable@freebsd.org, Roman Bogorodskiy References: <20070816143823.GA92480@svzserv.kemerovo.su> <20070816163132.BCBFF45048@ptavv.es.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20070816163132.BCBFF45048@ptavv.es.net> User-Agent: Mutt/1.5.16 (2007-06-09) Cc: freebsd-stable@freebsd.org, Artem Kuchin , Eugene Grosbein , Roman Bogorodskiy Subject: Re: panic after removing usb flash disk 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: Thu, 16 Aug 2007 17:08:18 -0000 On Thu, Aug 16, 2007 at 09:31:32AM -0700, Kevin Oberman wrote: > To further complicate things, many of the major contributors to FreeBSD > are only interested in it for its use as a server or embedded OS. This > means that they are willing to commit resources to SMP, which they need, > but not so willing for hot-removal of storage, which is of only slight > value in the server and embedded OS world. Really? Hmm. This got me thinking: it would benefit Juniper greatly if they 1) stopped using single disks in their multi-thousand-dollar routers (try dual disks with RAID 1), 2) stopped using ATA disks and went with SCSI, and 3) put in a hot-swap backplane of some sort. Nothing like paying US$20K for a ""enterprise"" product that uses single ATA disks with no hotswap capability. My point is that it WOULD benefit some of the major contributors to rank this issue as serious. > I am sure that a lot of people who have no professional interest in > fixing this do have a strong personal interest and I suspect that it > will happen before too long, but complaining about it is not really > going to help as almost every FreeBSD desktop and mobile user has been > bitten by this at one time or another and wants it fixed. The problem is that as computing changes and the hardware evolves, the underlying OS design being discussed here has not. There have been many real-life examples given where one cannot do anything about the circumstances that induce the panic (USB hub losing power due to a cat pulling the AC cord, laptops going into S1/S3 sleep mode, or server admins who need to go to the co-lo and perform some realtime data copying who simply forgot to umount). I've been told that Linux handles this anomaly, but that it's also configurable. I believe the default configuration is that the mount goes into read-only mode, and that if you want a panic (which many argue is the "right thing to do"), you can request such via mount -o/fstab. I'm glad that both sides of the "argument" agree that it's something that needs to get fixed. It's just an issue of when -- but the clock is ticking, and the world isn't going to wait... :-) -- | Jeremy Chadwick jdc at parodius.com | | Parodius Networking http://www.parodius.com/ | | UNIX Systems Administrator Mountain View, CA, USA | | Making life hard for others since 1977. PGP: 4BD6C0CB |