From mboxrd@z Thu Jan 1 00:00:00 1970 From: Miles Fidelman Subject: Re: rebuilding raided root partition Date: Sun, 05 Apr 2009 09:31:31 -0400 Message-ID: <49D8B2B3.7050903@traversetechnologies.com> References: <49D81804.6070102@traversetechnologies.com> <871vs7h9pe.fsf@frosties.localdomain> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <871vs7h9pe.fsf@frosties.localdomain> Sender: linux-raid-owner@vger.kernel.org To: Goswin von Brederlow Cc: linux-raid@vger.kernel.org List-Id: linux-raid.ids Goswin von Brederlow wrote: > Miles Fidelman writes: > > > my root partition is raided, and is now running only on its single > spare drive: > > ----- > server1:~# more /proc/mdstat md2 : inactive sdd3[0] sdb3[2] > 195318016 blocks > > server1:~# mdadm --detail /dev/md2 [details omitted] > /dev/md2: > Raid Level : raid1 > Device Size : 97659008 (93.13 GiB 100.00 GB) > Raid Devices : 2 > Total Devices : 2 > Preferred Minor : 2 > Persistence : Superblock is persistent > > State : active, degraded > Active Devices : 0 > Working Devices : 2 > Failed Devices : 0 > Spare Devices : 2 > > Number Major Minor RaidDevice State > 0 8 51 0 spare rebuilding /dev/sdd3 > 1 0 0 - removed > > 2 8 19 - spare /dev/sdb3 > > > You have 0 active devices and only spare devices. So there is nothing > to rebuild from. Looks like on top of your one drive failing you also > have a second drive that failed in that array or wasn't added to the > raid. Or the raid was running degraded before your drive failure. > > It is not running, it is inactive. There is nothing left to run. > That really is my question here... I've replaced the bad drive, and I'd like to have it come up and resync - which would give me an array that contains the replaced drive and the spare. I'm not sure why it's not happening. > >> so..... on to questions: >> >> 1. What's going on? >> >> 2. Any suggestions on how to reassemble the array? mdadm --assemble >> /dev/md2 tells me I need to deactivate the device, but then, it's my / >> volume - which leaves me a little stumped >> > > Ar you sure your / is actualy /dev/md2? Maybe you booted from > /dev/sda3 or /dev/sdc3? I recommend booting a rescue/life CD and > then look for a partition containing an active drive for md2 so you > can rebuild your raid. > pretty sure - there's a physical LVM volume defined on top of /dev/md2, and / is a LV defined on top of that - the machine comes up and runs > Also did you know that you can run a raid1 with 3 active drives? That > way you are potected against 2 drive failures and don't need to wait > for the spare drive to resync before having fault tolerance if one > drive fails. > > Can you elaborate on how to do that, particularly how to add a new active volume to an existing array? It seems like mdadm wants to add new disks as spares. Thanks, Miles