From: Carl Karsten <carl@personnelware.com>
To: linux-raid@vger.kernel.org
Subject: reconstruct raid superblock
Date: Wed, 16 Dec 2009 21:53:15 -0600 [thread overview]
Message-ID: <549053140912161953x665f84cbnc457c45e47ac2a97@mail.gmail.com> (raw)
I took over a box that had 1 ide boot drive, 6 sata raid drives (4
internal, 2 external.) I believe the 2 externals were redundant, so
could be removed. so I did, and mkfs-ed them. then I installed
ubuntu to the ide, and installed grub to sda, which turns out to be
the first sata. which would be fine if the raid was on sda1, but it
is on sda, and now the raid wont' assemble. no surprise, and I do
have a backup of the data spread across 5 external drives. but before
I abandon the array, I am wondering if I can fix it by recreating
mdadm's metatdata on sda, given I have sd[bcd] to work with.
any suggestions?
root@dhcp128:~# mdadm --examine /dev/sd[abcd]
mdadm: No md superblock detected on /dev/sda.
/dev/sdb:
Magic : a92b4efc
Version : 00.90.00
UUID : 8d0cf436:3fc2d2ef:93d71b24:b036cc6b
Creation Time : Wed Mar 25 21:04:08 2009
Raid Level : raid6
Used Dev Size : 1465137408 (1397.26 GiB 1500.30 GB)
Array Size : 5860549632 (5589.06 GiB 6001.20 GB)
Raid Devices : 6
Total Devices : 6
Preferred Minor : 0
Update Time : Tue Mar 31 23:08:02 2009
State : clean
Active Devices : 5
Working Devices : 6
Failed Devices : 1
Spare Devices : 1
Checksum : a4fbb93a - correct
Events : 8430
Chunk Size : 64K
Number Major Minor RaidDevice State
this 6 8 16 6 spare /dev/sdb
0 0 8 0 0 active sync /dev/sda
1 1 8 64 1 active sync /dev/sde
2 2 8 32 2 active sync /dev/sdc
3 3 8 48 3 active sync /dev/sdd
4 4 0 0 4 faulty removed
5 5 8 80 5 active sync
6 6 8 16 6 spare /dev/sdb
/dev/sdc:
Magic : a92b4efc
Version : 00.90.00
UUID : 8d0cf436:3fc2d2ef:93d71b24:b036cc6b
Creation Time : Wed Mar 25 21:04:08 2009
Raid Level : raid6
Used Dev Size : 1465137408 (1397.26 GiB 1500.30 GB)
Array Size : 5860549632 (5589.06 GiB 6001.20 GB)
Raid Devices : 6
Total Devices : 4
Preferred Minor : 0
Update Time : Sun Jul 12 11:31:47 2009
State : clean
Active Devices : 4
Working Devices : 4
Failed Devices : 2
Spare Devices : 0
Checksum : a59452db - correct
Events : 580158
Chunk Size : 64K
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 0 0 1 faulty removed
2 2 8 32 2 active sync /dev/sdc
3 3 8 48 3 active sync /dev/sdd
4 4 0 0 4 faulty removed
5 5 8 96 5 active sync
/dev/sdd:
Magic : a92b4efc
Version : 00.90.00
UUID : 8d0cf436:3fc2d2ef:93d71b24:b036cc6b
Creation Time : Wed Mar 25 21:04:08 2009
Raid Level : raid6
Used Dev Size : 1465137408 (1397.26 GiB 1500.30 GB)
Array Size : 5860549632 (5589.06 GiB 6001.20 GB)
Raid Devices : 6
Total Devices : 4
Preferred Minor : 0
Update Time : Sun Jul 12 11:31:47 2009
State : clean
Active Devices : 4
Working Devices : 4
Failed Devices : 2
Spare Devices : 0
Checksum : a59452ed - correct
Events : 580158
Chunk Size : 64K
Number Major Minor RaidDevice State
this 3 8 48 3 active sync /dev/sdd
0 0 8 0 0 active sync /dev/sda
1 1 0 0 1 faulty removed
2 2 8 32 2 active sync /dev/sdc
3 3 8 48 3 active sync /dev/sdd
4 4 0 0 4 faulty removed
5 5 8 96 5 active sync
--
Carl K
next reply other threads:[~2009-12-17 3:53 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-12-17 3:53 Carl Karsten [this message]
[not found] ` <70ed7c3e0912162117n3617556p3a8decef94f33a1c@mail.gmail.com>
[not found] ` <70ed7c3e0912162121v5df1b972x6d9176bdf7e27401@mail.gmail.com>
2009-12-17 6:18 ` reconstruct raid superblock Carl Karsten
[not found] ` <4877c76c0912162226w3dfbdbb2t4b13e016f53728a0@mail.gmail.com>
[not found] ` <549053140912162236l134c38a9v490ba172231e6b8c@mail.gmail.com>
2009-12-17 7:35 ` Michael Evans
2009-12-17 10:35 ` Majed B.
2009-12-17 11:22 ` Michael Evans
2009-12-17 11:45 ` Majed B.
2009-12-17 14:15 ` Carl Karsten
2009-12-17 14:39 ` Majed B.
2009-12-17 15:06 ` Carl Karsten
2009-12-17 15:40 ` Majed B.
2009-12-17 16:17 ` Carl Karsten
2009-12-17 18:07 ` Majed B.
2009-12-17 19:18 ` Michael Evans
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