From mboxrd@z Thu Jan 1 00:00:00 1970 From: Pavel Hofman Subject: Re: How to update homehost of an existing raid component Date: Mon, 19 Mar 2012 22:37:17 +0100 Message-ID: <4F67A70D.1020301@ivitera.com> References: <4F670361.6090902@ivitera.com> <20120320082828.0937662d@notabene.brown> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20120320082828.0937662d@notabene.brown> Sender: linux-raid-owner@vger.kernel.org To: NeilBrown Cc: linux RAID List-Id: linux-raid.ids Dne 19.3.2012 22:28, NeilBrown napsal(a): > On Mon, 19 Mar 2012 10:58:57 +0100 Pavel Hofman > wrote: > >> Hi, >> >> Please is there a way to update a homehost value for a specific raid >> component? >> >> md7 is raid1 composed of md5 and md6. UUID of md7 is listed in mdadm.conf: >> >> ARRAY /dev/md7 level=raid1 num-devices=2 metadata=01.00 >> UUID=dde16cd5:2e17c743:fcc7926c:fcf5081e >> >> >> Every time I reboot, md7 is auto assembled only from md5. When running >> manually, I get >> >> mdadm --verbose -A /dev/md7 --scan >> ... >> mdadm: /dev/md6 misses out due to wrong homehost >> ... >> > > There is something very strange here. > md5 and md6 look to some extent like different parts of the same RAID1. > They have the same Array UUID, the same "Update Time" and the same "Events" > counter. > However they have different "Creation Time" (19/Jan/2011 vs 17/Jun/2010) and > different names ("orfeus:7" vs "'orpheus':7"). > > I cannot imagine how that would happen. > > mdadm notices they are different so it cannot use them both. It chooses md5 > over md6 as md5 has the 'correct' homehost name. > > Your best bet would be to re-create the array so it gets good clean metadata. > > mdadm -S /dev/md7 > mdadm -C /dev/md7 -l1 -n2 --assume-clean --metadata=1.0 /dev/md6 /dev/md5 > > should do it. If you want to keep the same uuid, add > --uuid=dde16cd5:2e17c743:fcc7926c:fcf5081e > Neil, thanks a lot for your help. The command worked fine, now both md5 and md6 have the same name. Regards, Pavel.