From mboxrd@z Thu Jan 1 00:00:00 1970 From: James Ralston Subject: Re: Question about recovery via mdadm Date: Sun, 16 Feb 2003 05:32:20 -0500 Sender: linux-raid-owner@vger.kernel.org Message-ID: <28330000.1045391539@shieldbreaker.l33tskillz.org> References: <15948.9979.534439.238616@notabene.cse.unsw.edu.au> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <15948.9979.534439.238616@notabene.cse.unsw.edu.au> Content-Disposition: inline To: Neil Brown , "Cress, Andrew R" Cc: linux-raid@vger.kernel.org List-Id: linux-raid.ids On 2003-02-14 at 10:15:07+1100 Neil Brown wrote: > On Thursday February 13, andrew.r.cress@intel.com wrote: > > > Solving why I got into this is another issue, but: Is there any > > way, once I'm in this predicament, to force a recovery to the > > spare, from userland (via mdadm)? > > No. Reconstrution should start automatically. There is no > mechanism to start it from user-space. You could try to hot-remove > and hot-add again, but if it didn't work the first time it is > unlikely to work the second time. > > It would appear to be a kernel bug. Are there any kernel messages? > An Oops or something? I'll bet that if Andrew checks his syslog carefully, he'll find that the mdrecovery process generated a kernel Oops: https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=82815 If this is what happened, then simply rebooting the system should cause the reconstruction to start. > Do you know if redhat:2.4.18-14 contains any patches particular to > md? I doubt that's the problem, as I tried backporting the vanilla md driver from 2.4.21-pre3 into Red Hat's kernel-2.4.18-19.8.0, and I could still Oops it. IMHO, the two most likely explanations are: 1. There's a bug in the md driver somewhere. 2. Red Hat has tweaked/changed something in the kernel that the md driver is relying on, and as a result, what the md driver is doing causes an Oops. Neil, if you want to try to track this down, I'll be happy to help in any way I can. (I don't have enough kernel hacking experience to track this down myself, alas.) Regards, -- James Ralston, Information Technology Software Engineering Institute Carnegie Mellon University, Pittsburgh, PA, USA