From mboxrd@z Thu Jan 1 00:00:00 1970 From: "H. Peter Anvin" Subject: Re: Linux mdadm superblock question. Date: Sun, 14 Feb 2010 13:18:16 -0800 Message-ID: <4B786898.8030309@zytor.com> References: <4877c76c1002111752h23e14f7aibe58a89181e6f493@mail.gmail.com> <4B77044B.1020609@zytor.com> <4B7719C1.1060400@zytor.com> <4B785C49.7010105@shiftmail.org> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <4B785C49.7010105@shiftmail.org> Sender: linux-raid-owner@vger.kernel.org To: Asdo Cc: Justin Piszcz , Michael Evans , linux-raid@vger.kernel.org, linux-kernel@vger.kernel.org List-Id: linux-raid.ids On 02/14/2010 12:25 PM, Asdo wrote: > I don't understand... > In a system we have, the root filesystem on a raid-6 which is on second > (and last) partitions of many disks. > It always assembled correctly, it never tried to assemble the whole device. > (on the first partition there is a raid1 with boot) > So what's the problem exactly with not marking the beginning? In Fedora 12, for example, Dracut tries to make the distinction between whole RAID device and a partition device, and utterly fails -- often resulting in data loss. With a pointer to the beginning this would have been a trivial thing to detect. IMO it would make sense to support autoassemble for 1.0 superblocks, and making them the default. The purpose would be to get everyone off 0.9. However, *any* default is better than 1.1. -hpa -- H. Peter Anvin, Intel Open Source Technology Center I work for Intel. I don't speak on their behalf.