Gentoo Archives: gentoo-user

From: Andrea Conti <alyf@××××.net>
To: gentoo-user@l.g.o
Subject: Re: [gentoo-user] recovering RAID from an old server
Date: Sat, 20 Feb 2010 15:23:56
Message-Id: 4B7FFE4B.30601@alyf.net
In Reply to: Re: [gentoo-user] recovering RAID from an old server by Iain Buchanan
1 > md: bind<hdg2,1>
2 > md: bind<hde2,2>
3 > md: bind<hda2,3>
4 > raid1: raid set md100 active with 3 out of 4 mirrors
5
6 > md: bind<hdg5,1>
7 > md: bind<hde5,2>
8 > md: bind<hda5,3>
9 > raid1: raid set md101 active with 3 out of 4 mirrors
10
11 AFAICT this is all you need to know -- you definitely have two software
12 (mdraid) RAID 1 volumes:
13
14 md100 with hda2, hde2 and hdg2 as members
15 md101 with hda5, hde5 and hdg5 as members
16
17 Both arrays seem to have lost a member (I guess hdc2 and hdc5 respectively).
18
19 Honestly I don't know what is the point of running RAID1 volumes with
20 four mirrors, but that seems to be the way it was configured.
21
22 I would suggest that you take a *single* disk (let's say hdg) out of the
23 thing and hook it up to a fully functional Gentoo system with mdraid
24 (and of course XFS) compiled in the kernel and sys-fs/mdadm installed.
25
26 Then you can bring up each RAID volume in degraded state from the single
27 mirror:
28
29 #mdadm -A /dev/md100 -R /dev/hdX2
30 #mdadm -A /dev/md101 -R /dev/hdX5
31
32 (substiture hdX with the actual device name of the transplanted disk; in
33 any case mdadm has a very useful man page)
34
35 At this point you should be able to mount md100 and md101 *read-only*
36 and salvage any data you need.
37
38 Andrea

Replies

Subject Author
Re: [gentoo-user] recovering RAID from an old server Neil Bothwick <neil@××××××××××.uk>
Re: [gentoo-user] recovering RAID from an old server Iain Buchanan <iaindb@××××××××××××.au>