Re: 2 disk raid 5 failure
From: NeilBrown <hidden>
Date: 2014-10-05 08:41:05
On Sat, 4 Oct 2014 22:43:01 -0700 Jean-Paul Sergent [off-list ref] 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)
--
To unsubscribe from this list: send the line "unsubscribe linux-raid" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html Attachments
- (unnamed) [application/pgp-signature] 828 bytes