From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Leslie Rhorer" Subject: RE: Help! I killed my mdadm raid 5 Date: Thu, 18 Nov 2010 19:32:06 -0600 Message-ID: <8F.28.07087.893D5EC4@cdptpa-omtalb.mail.rr.com> References: <20101118195109.1GA4L.64443.root@cdptpa-web04-z02> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20101118195109.1GA4L.64443.root@cdptpa-web04-z02> Sender: linux-raid-owner@vger.kernel.org To: p3-500@roadrunner.com, linux-raid@vger.kernel.org List-Id: linux-raid.ids > -----Original Message----- > From: linux-raid-owner@vger.kernel.org [mailto:linux-raid- > owner@vger.kernel.org] On Behalf Of p3-500@roadrunner.com > Sent: Thursday, November 18, 2010 1:51 PM > To: linux-raid@vger.kernel.org > Subject: Help! I killed my mdadm raid 5 > > Arrg, Major goof. I managed to kill my raid 5 through my own stupidity. > Here is the chain of events, Your help is greatly appreciated. > > I added disk #6 to my working 5 disk array, after about 24 hours it was > done but i did not see the extra space (I now know all I needed to do was > fsck and resize). > > I failed and removed the new disk from the array then somehow also failed > and removed drive # 5 from the array. At this point the array was still > running so I added drive #5 & 6 back to the array but they got added as > spares instead of active components. next I rebooted and could not > assemble the array. > > I tried --assemble and --assemble --force which results with "mdadm: > /dev/md0 assembled from 4 drives and 1 spare - not enough to start the > array". I am naming all 6 drives on the command line. > > Several posts have suggested I --create the array again but I am hesitant > to do this as I do not want to lose my data. Yep, that's it. I would carefully inspect each drive using --examine to determine its proper place, but the two failed drives are a bit of a craps shoot, since you have already overwritten their metafiles. I would assemble the array in read-only mode and then read-only fsck the unmounted file system. IF this passes, the do a read-write fsck. Finally, mount the file system read-only and test the data well before continuing. The first file system access should trigger a resync. When creating the array, use the --assume-clean option so no resync will occur.