From: Nagilum <nagilum@nagilum.org>
To: linux-raid@vger.kernel.org
Cc: Neil Brown <neilb@suse.de>
Subject: Re: Help RAID5 reshape Oops / backup-file
Date: Thu, 11 Oct 2007 14:25:18 +0200 [thread overview]
Message-ID: <20071011142518.igm1jud7ms408ggg@cakebox.homeunix.net> (raw)
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Ok, after looking in "Grow.c" I can see that the backup file is
removed once the critial section has passed:
if (backup_file)
unlink(backup_file);
printf(Name ": ... critical section passed.\n");
Since I had passed that point I'll try to find out where
Grow_restart() stumbles. By looking at it I'm not even sure it's able
to "resume" and not just restart. :-/
----- Message from nagilum@nagilum.org ---------
Date: Tue, 09 Oct 2007 20:58:47 +0200
From: Nagilum <nagilum@nagilum.org>
Reply-To: Nagilum <nagilum@nagilum.org>
Subject: Help RAID5 reshape Oops / backup-file
To: linux-raid@vger.kernel.org
> Hi,
> During the process of reshaping a Raid5 from 3 (/dev/sd[a-c]) to 5
> devices (/dev/sd[a-e]) the system was accidentally shut down.
> I know I was stupid I should have used a --backup-file but stupid me didn't.
> Thanks for not rubbing it any further. :(
> Ok, here is what I have:
>
> nas:~# uname -a
> Linux nas 2.6.18-5-amd64 #1 SMP Thu Aug 30 01:14:54 UTC 2007 x86_64 GNU/Linux
> nas:~# mdadm --version
> mdadm - v2.5.6 - 9 November 2006
> nas:~# mdadm -Q --detail /dev/md0
> /dev/md0:
> Version : 00.91.03
> Creation Time : Sat Sep 15 21:11:41 2007
> Raid Level : raid5
> Device Size : 488308672 (465.69 GiB 500.03 GB)
> Raid Devices : 5
> Total Devices : 5
> Preferred Minor : 0
> Persistence : Superblock is persistent
>
> Update Time : Mon Oct 8 23:59:27 2007
> State : active, degraded, Not Started
> Active Devices : 3
> Working Devices : 5
> Failed Devices : 0
> Spare Devices : 2
>
> Layout : left-symmetric
> Chunk Size : 16K
>
> Delta Devices : 2, (3->5)
>
> UUID : 25da80a6:d56eb9d6:0d7656f3:2f233380
> Events : 0.470134
>
> Number Major Minor RaidDevice State
> 0 8 0 0 active sync /dev/sda
> 1 8 16 1 active sync /dev/sdb
> 2 8 32 2 active sync /dev/sdc
> 3 0 0 3 removed
> 4 0 0 4 removed
>
> 5 8 48 - spare /dev/sdd
> 6 8 64 - spare /dev/sde
>
>
> nas:~# mdadm -E /dev/sd[a-e]
> /dev/sda:
> Magic : a92b4efc
> Version : 00.91.00
> UUID : 25da80a6:d56eb9d6:0d7656f3:2f233380
> Creation Time : Sat Sep 15 21:11:41 2007
> Raid Level : raid5
> Device Size : 488308672 (465.69 GiB 500.03 GB)
> Array Size : 1953234688 (1862.75 GiB 2000.11 GB)
> Raid Devices : 5
> Total Devices : 5
> Preferred Minor : 0
>
> Reshape pos'n : 872095808 (831.70 GiB 893.03 GB)
> Delta Devices : 2 (3->5)
>
> Update Time : Mon Oct 8 23:59:27 2007
> State : clean
> Active Devices : 5
> Working Devices : 5
> Failed Devices : 0
> Spare Devices : 0
> Checksum : f425054d - correct
> Events : 0.470134
>
> Layout : left-symmetric
> Chunk Size : 16K
>
> Number Major Minor RaidDevice State
> this 0 8 0 0 active sync /dev/sda
>
> 0 0 8 0 0 active sync /dev/sda
> 1 1 8 16 1 active sync /dev/sdb
> 2 2 8 32 2 active sync /dev/sdc
> 3 3 8 64 3 active sync /dev/sde
> 4 4 8 48 4 active sync /dev/sdd
> /dev/sdb:
> Magic : a92b4efc
> Version : 00.91.00
> UUID : 25da80a6:d56eb9d6:0d7656f3:2f233380
> Creation Time : Sat Sep 15 21:11:41 2007
> Raid Level : raid5
> Device Size : 488308672 (465.69 GiB 500.03 GB)
> Array Size : 1953234688 (1862.75 GiB 2000.11 GB)
> Raid Devices : 5
> Total Devices : 5
> Preferred Minor : 0
>
> Reshape pos'n : 872095808 (831.70 GiB 893.03 GB)
> Delta Devices : 2 (3->5)
>
> Update Time : Mon Oct 8 23:59:27 2007
> State : clean
> Active Devices : 5
> Working Devices : 5
> Failed Devices : 0
> Spare Devices : 0
> Checksum : f425055f - correct
> Events : 0.470134
>
> Layout : left-symmetric
> Chunk Size : 16K
>
> Number Major Minor RaidDevice State
> this 1 8 16 1 active sync /dev/sdb
>
> 0 0 8 0 0 active sync /dev/sda
> 1 1 8 16 1 active sync /dev/sdb
> 2 2 8 32 2 active sync /dev/sdc
> 3 3 8 64 3 active sync /dev/sde
> 4 4 8 48 4 active sync /dev/sdd
> /dev/sdc:
> Magic : a92b4efc
> Version : 00.91.00
> UUID : 25da80a6:d56eb9d6:0d7656f3:2f233380
> Creation Time : Sat Sep 15 21:11:41 2007
> Raid Level : raid5
> Device Size : 488308672 (465.69 GiB 500.03 GB)
> Array Size : 1953234688 (1862.75 GiB 2000.11 GB)
> Raid Devices : 5
> Total Devices : 5
> Preferred Minor : 0
>
> Reshape pos'n : 872095808 (831.70 GiB 893.03 GB)
> Delta Devices : 2 (3->5)
>
> Update Time : Mon Oct 8 23:59:27 2007
> State : clean
> Active Devices : 5
> Working Devices : 5
> Failed Devices : 0
> Spare Devices : 0
> Checksum : f4250571 - correct
> Events : 0.470134
>
> Layout : left-symmetric
> Chunk Size : 16K
>
> Number Major Minor RaidDevice State
> this 2 8 32 2 active sync /dev/sdc
>
> 0 0 8 0 0 active sync /dev/sda
> 1 1 8 16 1 active sync /dev/sdb
> 2 2 8 32 2 active sync /dev/sdc
> 3 3 8 64 3 active sync /dev/sde
> 4 4 8 48 4 active sync /dev/sdd
> /dev/sdd:
> Magic : a92b4efc
> Version : 00.91.00
> UUID : 25da80a6:d56eb9d6:0d7656f3:2f233380
> Creation Time : Sat Sep 15 21:11:41 2007
> Raid Level : raid5
> Device Size : 488308672 (465.69 GiB 500.03 GB)
> Array Size : 1953234688 (1862.75 GiB 2000.11 GB)
> Raid Devices : 5
> Total Devices : 5
> Preferred Minor : 0
>
> Reshape pos'n : 872095808 (831.70 GiB 893.03 GB)
> Delta Devices : 2 (3->5)
>
> Update Time : Mon Oct 8 23:59:27 2007
> State : clean
> Active Devices : 5
> Working Devices : 5
> Failed Devices : 0
> Spare Devices : 0
> Checksum : f42505b9 - correct
> Events : 0.470134
>
> Layout : left-symmetric
> Chunk Size : 16K
>
> Number Major Minor RaidDevice State
> this 5 8 48 -1 spare /dev/sdd
>
> 0 0 8 0 0 active sync /dev/sda
> 1 1 8 16 1 active sync /dev/sdb
> 2 2 8 32 2 active sync /dev/sdc
> 3 3 8 64 3 active sync /dev/sde
> 4 4 8 48 4 active sync /dev/sdd
> /dev/sde:
> Magic : a92b4efc
> Version : 00.91.00
> UUID : 25da80a6:d56eb9d6:0d7656f3:2f233380
> Creation Time : Sat Sep 15 21:11:41 2007
> Raid Level : raid5
> Device Size : 488308672 (465.69 GiB 500.03 GB)
> Array Size : 1953234688 (1862.75 GiB 2000.11 GB)
> Raid Devices : 5
> Total Devices : 5
> Preferred Minor : 0
>
> Reshape pos'n : 872095808 (831.70 GiB 893.03 GB)
> Delta Devices : 2 (3->5)
>
> Update Time : Mon Oct 8 23:59:27 2007
> State : clean
> Active Devices : 5
> Working Devices : 5
> Failed Devices : 0
> Spare Devices : 0
> Checksum : f42505db - correct
> Events : 0.470134
>
> Layout : left-symmetric
> Chunk Size : 16K
>
> Number Major Minor RaidDevice State
> this 6 8 64 -1 spare /dev/sde
>
> 0 0 8 0 0 active sync /dev/sda
> 1 1 8 16 1 active sync /dev/sdb
> 2 2 8 32 2 active sync /dev/sdc
> 3 3 8 64 3 active sync /dev/sde
> 4 4 8 48 4 active sync /dev/sdd
>
> nas:~# mdadm /dev/md0 -r /dev/sde
> mdadm: hot remove failed for /dev/sde: No such device
> nas:~# cat /proc/mdstat
> Personalities : [raid6] [raid5] [raid4]
> md0 : inactive sda[0] sdd[5](S) sde[6](S) sdc[2] sdb[1]
> 2441543360 blocks super 0.91
>
> unused devices: <none>
>
> So reshaping was almost done.
> The way I imagine how reshaping works you'd basically have an already
> remapped area growing from the start of the drives (which grows during
> remapping) and some not-yet-remapped-area which spans from the end of
> the drives towards wherever remapping is currently reading data from.
> At the beginning of the processing it equals the start of the drives
> but it shrinks faster than the remapped area grows. So there is a
> growing gap between the two areas which contains still original
> unmapped data.
> The point is, as soon as this area grows large enough the backup-file
> should become unneeded.
> Ok, now if mdadm wants me to provide that file I should also be able
> to re-create it using the "Reshape pos'n" and the drive geometry (and
> dd).
> Now the question is how to do it?
> I also have build mdadm-2.6.3 which appears to see things more clearly:
>
> nas:~/mdadm-2.6.3# ./mdadm -A /dev/md0 /dev/sd[a-e]
> mdadm: Failed to restore critical section for reshape, sorry.
>
> So if I could create the backup file I should be able to continue..
> Any help would be greatly appreciated!
> Alexander.
----- End message from nagilum@nagilum.org -----
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next reply other threads:[~2007-10-11 12:25 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-10-11 12:25 Nagilum [this message]
2007-10-11 23:51 ` Help RAID5 reshape Oops / backup-file Neil Brown
2007-10-12 6:43 ` Nagilum
2007-10-14 16:55 ` Nagilum
2007-10-14 23:31 ` Neil Brown
2007-10-15 11:55 ` Nagilum
2007-10-15 12:08 ` Nagilum
2007-10-16 1:16 ` Neil Brown
2007-10-16 12:50 ` Nagilum
2007-10-17 13:13 ` Nagilum
-- strict thread matches above, loose matches on Subject: below --
2007-10-09 18:58 Nagilum
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