Hello, Please consider the following RAID5 recovery attempt after a
failed partial reshape.
Copy-on-write devices were created to protect original drives.
Any assistance on how to reassemble would be most welcome.
...Operating environment is from a systemrescuecd...
% mdadm -V
mdadm - v3.1.4 - 31st August 2010
% /usr/local/sbin/mdadm -V <<<<<< compiled latest by hand
mdadm - v3.2.6 - 25th October 2012
% uname -a
Linux dallas 3.2.33-std311-amd64 #2 SMP Wed Oct 31 07:31:30 UTC 2012
x86_64 Intel(R) Core(TM) i7-2600K CPU @ 3.40GHz GenuineIntel GNU/Linux
...Drive /dev/mapper/cow_sdc1 appears damaged and goes offline
sporadically, so I'm trying to reassemble with out sdc1...
...In any case sdc1 is out of sync with the other drives and it's
reshape pos'n is at zero...
...Also /usb/foo is an empty file...
% export MDADM_GROW_ALLOW_OLD=1
% /usr/local/sbin/mdadm -vv --assemble --force
--backup-file=/usb/foo /dev/md2 /dev/mapper/cow_sdd1
/dev/mapper/cow_sde1 /dev/mapper/cow_sdf1 /dev/mapper/cow_sdg1
/dev/mapper/cow_sdh1
mdadm: looking for devices for /dev/md2
mdadm: /dev/mapper/cow_sdd1 is identified as a member of /dev/md2, slot 1.
mdadm: /dev/mapper/cow_sde1 is identified as a member of /dev/md2, slot 2.
mdadm: /dev/mapper/cow_sdf1 is identified as a member of /dev/md2, slot -1.
mdadm: /dev/mapper/cow_sdg1 is identified as a member of /dev/md2, slot 4.
mdadm: /dev/mapper/cow_sdh1 is identified as a member of /dev/md2, slot 5.
mdadm:/dev/md2 has an active reshape - checking if critical section
needs to be restored
mdadm: Cannot read from /usb/foo
mdadm: accepting backup with timestamp 1372908503 for array with
timestamp 1373237070
mdadm: backup-metadata found on device-5 but is not needed
mdadm: No backup metadata on device-6
mdadm: no uptodate device for slot 0 of /dev/md2
mdadm: added /dev/mapper/cow_sde1 to /dev/md2 as 2
mdadm: no uptodate device for slot 3 of /dev/md2
mdadm: added /dev/mapper/cow_sdg1 to /dev/md2 as 4
mdadm: added /dev/mapper/cow_sdh1 to /dev/md2 as 5
mdadm: added /dev/mapper/cow_sdf1 to /dev/md2 as -1 (possibly out of date)
mdadm: added /dev/mapper/cow_sdd1 to /dev/md2 as 1
mdadm: /dev/md2 assembled from 4 drives - not enough to start the array.
...Noticed a difference to mdstat after --run, not sure if it is significant...
% cat /proc/mdstat
Personalities : [linear] [multipath] [raid0] [raid1] [raid6] [raid5]
[raid4] [raid10]
md2 : inactive dm-1[5](S) dm-5[4](S) dm-9[7](S) dm-7[6](S) dm-3[3](S)
<<<<<<<<<<<< note five (S)'s
14650675369 blocks super 1.2
unused devices: <none>
% /usr/local/sbin/mdadm -vv --run /dev/md2
mdadm: failed to run array /dev/md2: Input/output error
% cat /proc/mdstat
Personalities : [linear] [multipath] [raid0] [raid1] [raid6] [raid5]
[raid4] [raid10]
md2 : inactive dm-1[5] dm-5[4](F) dm-9[7] dm-7[6] dm-3[3]
<<<<<<<<<<<< note difference
11720539894 blocks super 1.2
unused devices: <none>
....Info from mdadm --examine...
mdadm -E /dev/mapper/cow_sdc1 /dev/mapper/cow_sdd1
/dev/mapper/cow_sde1 /dev/mapper/cow_sdf1 /dev/mapper/cow_sdg1
/dev/mapper/cow_sdh1
/dev/mapper/cow_sdc1:
Magic : a92b4efc
Version : 1.2
Feature Map : 0x4
Array UUID : a0071bbe:16fe9e3b:76ce40a8:754d0200
Name : tron:0
Creation Time : Sat Dec 22 23:26:19 2012
Raid Level : raid5
Raid Devices : 6
Avail Dev Size : 5862022855 (2795.23 GiB 3001.36 GB)
Array Size : 29301340160 (13971.97 GiB 15002.29 GB)
Used Dev Size : 5860268032 (2794.39 GiB 3000.46 GB)
Data Offset : 262144 sectors
Super Offset : 8 sectors
State : clean
Device UUID : 9eacfd8d:92eb403b:4408be7f:601e36b5
Reshape pos'n : 0
<<<<<< reshape at zero
Delta Devices : 1 (5->6)
Update Time : Thu Jul 4 03:27:43 2013 <<<<<< out of sync
Checksum : 14fae7a3 - correct
Events : 125183
Layout : left-symmetric
Chunk Size : 512K
Device Role : Active device 0
Array State : AAAAAA ('A' == active, '.' == missing)
/dev/mapper/cow_sdd1:
Magic : a92b4efc
Version : 1.2
Feature Map : 0x4
Array UUID : a0071bbe:16fe9e3b:76ce40a8:754d0200
Name : tron:0
Creation Time : Sat Dec 22 23:26:19 2012
Raid Level : raid5
Raid Devices : 6
Avail Dev Size : 5860270951 (2794.40 GiB 3000.46 GB)
Array Size : 29301340160 (13971.97 GiB 15002.29 GB)
Used Dev Size : 5860268032 (2794.39 GiB 3000.46 GB)
Data Offset : 262144 sectors
Super Offset : 8 sectors
State : clean
Device UUID : 81087206:02b470b1:6c06cb8b:63c79b21
Reshape pos'n : 12080240640 (11520.62 GiB 12370.17 GB)
Delta Devices : 1 (5->6)
Update Time : Sun Jul 7 22:44:30 2013
Checksum : 1c10ab66 - correct
Events : 125181
Layout : left-symmetric
Chunk Size : 512K
Device Role : Active device 1
Array State : .AAAAA ('A' == active, '.' == missing)
/dev/mapper/cow_sde1:
Magic : a92b4efc
Version : 1.2
Feature Map : 0x4
Array UUID : a0071bbe:16fe9e3b:76ce40a8:754d0200
Name : tron:0
Creation Time : Sat Dec 22 23:26:19 2012
Raid Level : raid5
Raid Devices : 6
Avail Dev Size : 5860268943 (2794.39 GiB 3000.46 GB)
Array Size : 29301340160 (13971.97 GiB 15002.29 GB)
Used Dev Size : 5860268032 (2794.39 GiB 3000.46 GB)
Data Offset : 262144 sectors
Super Offset : 8 sectors
State : clean
Device UUID : a7d341d2:392c9c31:0e28e8e2:865b56a9
Reshape pos'n : 12080240640 (11520.62 GiB 12370.17 GB)
Delta Devices : 1 (5->6)
Update Time : Sun Jul 7 22:44:30 2013
Checksum : 46e39caf - correct
Events : 125181
Layout : left-symmetric
Chunk Size : 512K
Device Role : Active device 2
Array State : .AAAAA ('A' == active, '.' == missing)
/dev/mapper/cow_sdf1:
Magic : a92b4efc
Version : 1.2
Feature Map : 0x6
Array UUID : a0071bbe:16fe9e3b:76ce40a8:754d0200
Name : tron:0
Creation Time : Sat Dec 22 23:26:19 2012
Raid Level : raid5
Raid Devices : 6
Avail Dev Size : 5860270951 (2794.40 GiB 3000.46 GB)
Array Size : 29301340160 (13971.97 GiB 15002.29 GB)
Used Dev Size : 5860268032 (2794.39 GiB 3000.46 GB)
Data Offset : 262144 sectors
Super Offset : 8 sectors
Recovery Offset : 4832096256 sectors
State : active
Device UUID : 332d8290:ec203a26:df299919:9f779aa7
Reshape pos'n : 12080240640 (11520.62 GiB 12370.17 GB)
Delta Devices : 1 (5->6)
Update Time : Sun Jul 7 22:45:42 2013
Checksum : 4eaf00f5 - correct
Events : 125183
Layout : left-symmetric
Chunk Size : 512K
Device Role : spare
Array State : ...... ('A' == active, '.' == missing)
/dev/mapper/cow_sdg1:
Magic : a92b4efc
Version : 1.2
Feature Map : 0x4
Array UUID : a0071bbe:16fe9e3b:76ce40a8:754d0200
Name : tron:0
Creation Time : Sat Dec 22 23:26:19 2012
Raid Level : raid5
Raid Devices : 6
Avail Dev Size : 5860270951 (2794.40 GiB 3000.46 GB)
Array Size : 29301340160 (13971.97 GiB 15002.29 GB)
Used Dev Size : 5860268032 (2794.39 GiB 3000.46 GB)
Data Offset : 262144 sectors
Super Offset : 8 sectors
State : clean
Device UUID : ca37a376:12fa661f:844f2740:cab22de8
Reshape pos'n : 12080240640 (11520.62 GiB 12370.17 GB)
Delta Devices : 1 (5->6)
Update Time : Sun Jul 7 22:44:30 2013
Checksum : 7526553f - correct
Events : 125181
Layout : left-symmetric
Chunk Size : 512K
Device Role : Active device 4
Array State : .AAAAA ('A' == active, '.' == missing)
/dev/mapper/cow_sdh1:
Magic : a92b4efc
Version : 1.2
Feature Map : 0x4
Array UUID : a0071bbe:16fe9e3b:76ce40a8:754d0200
Name : tron:0
Creation Time : Sat Dec 22 23:26:19 2012
Raid Level : raid5
Raid Devices : 6
Avail Dev Size : 5860268943 (2794.39 GiB 3000.46 GB)
Array Size : 29301340160 (13971.97 GiB 15002.29 GB)
Used Dev Size : 5860268032 (2794.39 GiB 3000.46 GB)
Data Offset : 262144 sectors
Super Offset : 8 sectors
State : clean
Device UUID : e02598c3:708630c9:e666b0cf:4189fbb0
Reshape pos'n : 12080240640 (11520.62 GiB 12370.17 GB)
Delta Devices : 1 (5->6)
Update Time : Sun Jul 7 22:44:30 2013
Checksum : c43bb5b6 - correct
Events : 125181
Layout : left-symmetric
Chunk Size : 512K
Device Role : Active device 5
Array State : .AAAAA ('A' == active, '.' == missing)
...Thank you for your help. Veedar...
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