From mboxrd@z Thu Jan 1 00:00:00 1970 From: Goswin von Brederlow Subject: Re: md homehost Date: Tue, 23 Feb 2010 08:31:16 +0100 Message-ID: <87635opfwb.fsf@frosties.localdomain> References: <20100218044004.GC5136@lapse.rw.madduck.net> <20100218161012.704b43a6@notabene.brown> <20100218052145.GA7178@lapse.rw.madduck.net> <20100218163448.0d3f3107@notabene.brown> <20100219004237.GC25162@lapse.rw.madduck.net> <20100219091619.GA2964@lazy.lzy> <20100221174007.GB19058@lapse.rw.madduck.net> <20100221201304.GB2570@lazy.lzy> <20100222091632.GE2641@lapse.rw.madduck.net> <20100223133028.279e0174@notabene.brown> <20100223062700.GB19666@lapse.rw.madduck.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: In-Reply-To: <20100223062700.GB19666@lapse.rw.madduck.net> (martin f. krafft's message of "Tue, 23 Feb 2010 07:27:00 +0100") Sender: linux-raid-owner@vger.kernel.org To: Neil Brown Cc: Piergiorgio Sartor , 567468@bugs.debian.org, Daniel Reurich , linux-raid List-Id: linux-raid.ids martin f krafft writes: > also sprach Neil Brown [2010.02.23.0330 +0100]: >> The problem to protect against is any consequence of rearranging >> devices while the host is off, including attaching devices that >> previously were attached to a different computer. > > How often does this happen, and how grave/dangerous are the effects? > >> But if '/' is mounted by a name in /dev/md/, I want to be sure >> mdadm puts the correct array at that name no matter what other >> arrays might be visible. > > Of course it would be nice if this happened, but wouldn't it be > acceptable to assume that if someone swaps drives between machines > that they ought to know how to deal with the consequences, or at > least be ready to tae additional steps to make sure the system still > boots as desired? > > Even if the wrong array appeared as /dev/md0 and was mounted as root > device, is there any actual problem, other than inconvenience? > Remember that the person who has previously swapped the drives is > physically in front of (or behind ;)) the machine. > > I am unconvinced. I think we should definitely switch to using > filesystem-UUIDs over device names, and that is the only real > solution to the problem, no? Both filesystems and LVM have UUIDs. Does dm-crypt / LUKS have one too? MfG Goswin