From: NeilBrown <neilb@suse.de>
To: Jean-Paul Sergent <jpsergent@gmail.com>
Cc: linux-raid@vger.kernel.org
Subject: Re: 2 disk raid 5 failure
Date: Sun, 5 Oct 2014 19:41:05 +1100 [thread overview]
Message-ID: <20141005194105.4377c295@notabene.brown> (raw)
In-Reply-To: <CANuKpt=QJsham0TQWR1Cu1EC8GLyc0aSdU4p3DOznBRrEea11A@mail.gmail.com>
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On Sat, 4 Oct 2014 22:43:01 -0700 Jean-Paul Sergent <jpsergent@gmail.com>
wrote:
> Greetings,
>
> Recently I lost 2 disks, out of 5, in my raid 5 array from a bad SATA power
> cable. It was a Y splitter and it shorted... it was cheap. I was wondering
> if there was any chance in getting my data back.
>
> Of the 2 disks that blew out, one actually had bad/unreadable sectors on
> the disk and the other disk seems fine. I have cloned both disks with DD to
> 2 new disks and forced the one disk to clone even with errors. The
> remaining 3 disks are in tact. The events number on the array for all 5
> disks are very close to each other:
>
> Events : 201636
> Events : 201636
> Events : 201636
> Events : 201630
> Events : 201633
>
> Which from my reading gives me some hope, but I'm not sure. I have not done
> "recovering a failed software raid" on the wiki yet, the part about
> using a loop device to protect your array. I thought I would send a
> message out to this list first before going down
> that route.
>
> I did try to do a mdadm --force --assemble on the array but is says that it
> only has 3 disks which isn't enough to start the array. I don't want to do
> anything else before consulting the mailing list first.
--force --assemble really is what you want. It should work.
What does
mdadm -A /dev/md1 --force -vv /dev/sdb /dev/sdc /dev/sde /dev/sdf /dev/sdg
report??
What version of mdadm (mdadm -V) do you have?
NeilBrown
>
> below I have pasted the mdadm --examine from each member drive. Any help would
> be greatly appreciated.
>
> Thanks,
> -JP
>
> /dev/sdb:
> Magic : a92b4efc
> Version : 1.2
> Feature Map : 0x0
> Array UUID : 7de100f5:4f30f751:62456293:fe98f735
> Name : b1ackb0x:1
> Creation Time : Sun Jan 13 00:01:44 2013
> Raid Level : raid5
> Raid Devices : 5
>
> Avail Dev Size : 2930275120 (1397.26 GiB 1500.30 GB)
> Array Size : 5860548608 (5589.05 GiB 6001.20 GB)
> Used Dev Size : 2930274304 (1397.26 GiB 1500.30 GB)
> Data Offset : 2048 sectors
> Super Offset : 8 sectors
> Unused Space : before=1968 sectors, after=816 sectors
> State : clean
> Device UUID : 71d7c3d7:7b232399:51571715:711da6f6
>
> Update Time : Tue Apr 29 02:49:21 2014
> Checksum : cd29f83c - correct
> Events : 201636
>
> Layout : left-symmetric
> Chunk Size : 512K
>
> Device Role : Active device 2
> Array State : AAA.. ('A' == active, '.' == missing, 'R' == replacing)
> /dev/sdc:
> Magic : a92b4efc
> Version : 1.2
> Feature Map : 0x0
> Array UUID : 7de100f5:4f30f751:62456293:fe98f735
> Name : b1ackb0x:1
> Creation Time : Sun Jan 13 00:01:44 2013
> Raid Level : raid5
> Raid Devices : 5
>
> Avail Dev Size : 2930275120 (1397.26 GiB 1500.30 GB)
> Array Size : 5860548608 (5589.05 GiB 6001.20 GB)
> Used Dev Size : 2930274304 (1397.26 GiB 1500.30 GB)
> Data Offset : 2048 sectors
> Super Offset : 8 sectors
> Unused Space : before=1968 sectors, after=816 sectors
> State : clean
> Device UUID : b47c32b5:b2f9e81a:37150c33:8e3fa6ca
>
> Update Time : Tue Apr 29 02:49:21 2014
> Checksum : 1e5353af - correct
> Events : 201636
>
> Layout : left-symmetric
> Chunk Size : 512K
>
> Device Role : Active device 1
> Array State : AAA.. ('A' == active, '.' == missing, 'R' == replacing)
> /dev/sde:
> Magic : a92b4efc
> Version : 1.2
> Feature Map : 0x0
> Array UUID : 7de100f5:4f30f751:62456293:fe98f735
> Name : b1ackb0x:1
> Creation Time : Sun Jan 13 00:01:44 2013
> Raid Level : raid5
> Raid Devices : 5
>
> Avail Dev Size : 2930275120 (1397.26 GiB 1500.30 GB)
> Array Size : 5860548608 (5589.05 GiB 6001.20 GB)
> Used Dev Size : 2930274304 (1397.26 GiB 1500.30 GB)
> Data Offset : 2048 sectors
> Super Offset : 8 sectors
> Unused Space : before=1968 sectors, after=816 sectors
> State : clean
> Device UUID : 0398da5b:0bcddd81:8f7e77e9:6689ee0c
>
> Update Time : Tue Apr 29 02:49:21 2014
> Checksum : 24a3f586 - correct
> Events : 201636
>
> Layout : left-symmetric
> Chunk Size : 512K
>
> Device Role : Active device 0
> Array State : AAA.. ('A' == active, '.' == missing, 'R' == replacing)
> /dev/sdf:
> Magic : a92b4efc
> Version : 1.2
> Feature Map : 0x0
> Array UUID : 7de100f5:4f30f751:62456293:fe98f735
> Name : b1ackb0x:1
> Creation Time : Sun Jan 13 00:01:44 2013
> Raid Level : raid5
> Raid Devices : 5
>
> Avail Dev Size : 2930275120 (1397.26 GiB 1500.30 GB)
> Array Size : 5860548608 (5589.05 GiB 6001.20 GB)
> Used Dev Size : 2930274304 (1397.26 GiB 1500.30 GB)
> Data Offset : 2048 sectors
> Super Offset : 8 sectors
> Unused Space : before=1968 sectors, after=976752816 sectors
> State : clean
> Device UUID : 356c6d85:627a994f:753dec0d:db4fa4f2
>
> Update Time : Tue Apr 29 02:37:38 2014
> Checksum : 2621f9d5 - correct
> Events : 201630
>
> Layout : left-symmetric
> Chunk Size : 512K
>
> Device Role : Active device 3
> Array State : AAAAA ('A' == active, '.' == missing, 'R' == replacing)
> /dev/sdg:
> Magic : a92b4efc
> Version : 1.2
> Feature Map : 0x0
> Array UUID : 7de100f5:4f30f751:62456293:fe98f735
> Name : b1ackb0x:1
> Creation Time : Sun Jan 13 00:01:44 2013
> Raid Level : raid5
> Raid Devices : 5
>
> Avail Dev Size : 2930275120 (1397.26 GiB 1500.30 GB)
> Array Size : 5860548608 (5589.05 GiB 6001.20 GB)
> Used Dev Size : 2930274304 (1397.26 GiB 1500.30 GB)
> Data Offset : 2048 sectors
> Super Offset : 8 sectors
> Unused Space : before=1968 sectors, after=976752816 sectors
> State : clean
> Device UUID : 3dc152d8:832dd43a:a6d638e3:6e12b394
>
> Update Time : Tue Apr 29 02:48:01 2014
> Checksum : db9e6008 - correct
> Events : 201633
>
> Layout : left-symmetric
> Chunk Size : 512K
>
> Device Role : Active device 4
> Array State : AAA.A ('A' == active, '.' == missing, 'R' == replacing)
> --
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> More majordomo info at http://vger.kernel.org/majordomo-info.html
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next prev parent reply other threads:[~2014-10-05 8:41 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-10-05 5:43 2 disk raid 5 failure Jean-Paul Sergent
2014-10-05 8:41 ` NeilBrown [this message]
2014-10-05 9:21 ` Jean-Paul Sergent
2014-10-05 9:38 ` Jean-Paul Sergent
2014-10-05 9:52 ` NeilBrown
2014-10-05 9:55 ` Jean-Paul Sergent
2014-10-05 23:50 ` NeilBrown
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