From mboxrd@z Thu Jan 1 00:00:00 1970 From: Brice Figureau Subject: Same UUID for every member of all array ? Date: Thu, 12 Apr 2007 14:57:57 +0200 Message-ID: <1176382677.14496.17.camel@localhost.localdomain> Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Return-path: Sender: linux-raid-owner@vger.kernel.org To: linux-raid@vger.kernel.org List-Id: linux-raid.ids Hi, While I was trying to understand while an old server (which was happily running linux 2.6.16 without initrd) was not booting anymore after a migration to Etch and a new kernel (2.6.20.6 with initrd), I found the following issue: $ mdadm --detail --scan ARRAY /dev/md0 level=raid1 num-devices=2 UUID=6b8b4567:327b23c6:643c9869:66334873 ARRAY /dev/md8 level=raid1 num-devices=2 UUID=6b8b4567:327b23c6:643c9869:66334873 ARRAY /dev/md7 level=raid1 num-devices=2 UUID=6b8b4567:327b23c6:643c9869:66334873 ARRAY /dev/md6 level=raid1 num-devices=2 UUID=6b8b4567:327b23c6:643c9869:66334873 ARRAY /dev/md5 level=raid1 num-devices=2 UUID=6b8b4567:327b23c6:643c9869:66334873 ARRAY /dev/md4 level=raid1 num-devices=2 UUID=6b8b4567:327b23c6:643c9869:66334873 ARRAY /dev/md3 level=raid1 num-devices=2 UUID=6b8b4567:327b23c6:643c9869:66334873 ARRAY /dev/md2 level=raid1 num-devices=2 UUID=6b8b4567:327b23c6:643c9869:66334873 ARRAY /dev/md1 level=raid1 num-devices=2 UUID=6b8b4567:327b23c6:643c9869:66334873 As you can see, all the UUIDs are the same, and indeed there is no possibility for mdadm to assemble such arrays as it uses the UUID to find matching members. Now, I don't know why all the UUID are equals (my other machines are not affected). Is there a possibility to "hot" change the UUID of each array (and change the corresponding superblocks of each member) so that my next boot will work ? I'm not subscribed to the list, so please CC: me on replies. Thanks, -- Brice Figureau