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Q: how to re-assemble RAID5 array
After some stupid action (described here) I lost a RAID5 volume (4 x 6TB, OS 4.2.27). The partitions vanished from the partition table. No warranty, no backup. It would be nice (though not essential) if I could get about 7TB of the data recovered.
Using a Pro6 with VGA breakout, I booted Knoppix off of a USB pendrive. Using cgsecurity's TestDisk I was able to recover the RAID5 partitions. Running some tests, the partitions seem to be OK to me, but I cannot assemble the array.
If anyone had experience with this and could give me some pointers it would be highly appreciated... ;)
This is what I did so far:
root@Microknoppix:/home/knoppix# cat /proc/mdstat cat: /proc/mdstat: No such file or directory root@Microknoppix:/home/knoppix# modprobe raid456 root@Microknoppix:/home/knoppix# cat /proc/mdstat Personalities : [raid6] [raid5] [raid4] unused devices: <none> root@Microknoppix:/home/knoppix# mdadm --examine --scan ARRAY /dev/md/0 metadata=1.2 UUID=8e3862b6:09a0547e:9f752f8b:a6e0267e name=001F33EA1AC5:0 ARRAY /dev/md/1 metadata=1.2 UUID=5d5efea4:7225f2e7:609f8fa4:9d414452 name=001F33EA1AC5:1 ARRAY /dev/md/2 metadata=1.2 UUID=b697ee5c:dfd93286:04cbc712:c960ad5b name=001F33EA1AC5:2
So it looks like the OS partition (md0), swap partition (md1) and data partition (md2) are there.
However, trying to assemble:
root@Microknoppix:/home/knoppix# mdadm --assemble --scan mdadm: failed to add /dev/sdb3 to /dev/md/001F33EA1AC5:2: Invalid argument mdadm: failed to add /dev/sdc3 to /dev/md/001F33EA1AC5:2: Invalid argument mdadm: failed to add /dev/sdd3 to /dev/md/001F33EA1AC5:2: Invalid argument mdadm: failed to add /dev/sda3 to /dev/md/001F33EA1AC5:2: Invalid argument mdadm: failed to RUN_ARRAY /dev/md/001F33EA1AC5:2: Invalid argument mdadm: failed to add /dev/sdb2 to /dev/md/001F33EA1AC5:1: Invalid argument mdadm: failed to add /dev/sdc2 to /dev/md/001F33EA1AC5:1: Invalid argument mdadm: failed to add /dev/sdd2 to /dev/md/001F33EA1AC5:1: Invalid argument mdadm: failed to add /dev/sda2 to /dev/md/001F33EA1AC5:1: Invalid argument mdadm: failed to RUN_ARRAY /dev/md/001F33EA1AC5:1: Invalid argument mdadm: failed to add /dev/sdb1 to /dev/md/001F33EA1AC5:0: Invalid argument mdadm: failed to add /dev/sdc1 to /dev/md/001F33EA1AC5:0: Invalid argument mdadm: failed to add /dev/sdd1 to /dev/md/001F33EA1AC5:0: Invalid argument mdadm: failed to add /dev/sda1 to /dev/md/001F33EA1AC5:0: Invalid argument mdadm: failed to RUN_ARRAY /dev/md/001F33EA1AC5:0: Invalid argument mdadm: No arrays found in config file or automatically
Examining all data partitions:
root@Microknoppix:/home/knoppix# mdadm --examine /dev/sd[abcd]3
/dev/sda3:
Magic : a92b4efc
Version : 1.2
Feature Map : 0x0
Array UUID : b697ee5c:dfd93286:04cbc712:c960ad5b
Name : 001F33EA1AC5:2
Creation Time : Mon Aug 17 20:52:14 2015
Raid Level : raid5
Raid Devices : 4
Avail Dev Size : 11711601777 (5584.53 GiB 5996.34 GB)
Array Size : 17567402112 (16753.58 GiB 17989.02 GB)
Used Dev Size : 11711601408 (5584.53 GiB 5996.34 GB)
Data Offset : 2048 sectors
Super Offset : 8 sectors
State : clean
Device UUID : 1f2351ff:d6b0ce48:adc5d480:052a9385
Update Time : Mon Aug 24 22:12:18 2015
Checksum : 251998ca - correct
Events : 99
Layout : left-symmetric
Chunk Size : 64K
Device Role : Active device 0
Array State : AAAA ('A' == active, '.' == missing)
/dev/sdb3:
Magic : a92b4efc
Version : 1.2
Feature Map : 0x0
Array UUID : b697ee5c:dfd93286:04cbc712:c960ad5b
Name : 001F33EA1AC5:2
Creation Time : Mon Aug 17 20:52:14 2015
Raid Level : raid5
Raid Devices : 4
Avail Dev Size : 11711601777 (5584.53 GiB 5996.34 GB)
Array Size : 17567402112 (16753.58 GiB 17989.02 GB)
Used Dev Size : 11711601408 (5584.53 GiB 5996.34 GB)
Data Offset : 2048 sectors
Super Offset : 8 sectors
State : clean
Device UUID : ad97e3fa:7010280a:2013be33:8fa98bb2
Update Time : Mon Aug 24 22:12:18 2015
Checksum : c1e739ef - correct
Events : 99
Layout : left-symmetric
Chunk Size : 64K
Device Role : Active device 1
Array State : AAAA ('A' == active, '.' == missing)
/dev/sdc3:
Magic : a92b4efc
Version : 1.2
Feature Map : 0x0
Array UUID : b697ee5c:dfd93286:04cbc712:c960ad5b
Name : 001F33EA1AC5:2
Creation Time : Mon Aug 17 20:52:14 2015
Raid Level : raid5
Raid Devices : 4
Avail Dev Size : 11711601777 (5584.53 GiB 5996.34 GB)
Array Size : 17567402112 (16753.58 GiB 17989.02 GB)
Used Dev Size : 11711601408 (5584.53 GiB 5996.34 GB)
Data Offset : 2048 sectors
Super Offset : 8 sectors
State : clean
Device UUID : 93aee45f:f0e48a25:1dc1448e:6956f9cc
Update Time : Mon Aug 24 22:12:18 2015
Checksum : b73f802d - correct
Events : 99
Layout : left-symmetric
Chunk Size : 64K
Device Role : Active device 2
Array State : AAAA ('A' == active, '.' == missing)
/dev/sdd3:
Magic : a92b4efc
Version : 1.2
Feature Map : 0x0
Array UUID : b697ee5c:dfd93286:04cbc712:c960ad5b
Name : 001F33EA1AC5:2
Creation Time : Mon Aug 17 20:52:14 2015
Raid Level : raid5
Raid Devices : 4
Avail Dev Size : 11711601777 (5584.53 GiB 5996.34 GB)
Array Size : 17567402112 (16753.58 GiB 17989.02 GB)
Used Dev Size : 11711601408 (5584.53 GiB 5996.34 GB)
Data Offset : 2048 sectors
Super Offset : 8 sectors
State : clean
Device UUID : e533daef:44960cd1:62926d25:0a6a4aa8
Update Time : Mon Aug 24 22:12:18 2015
Checksum : 65309bbb - correct
Events : 99
Layout : left-symmetric
Chunk Size : 64K
Device Role : Active device 3
Array State : AAAA ('A' == active, '.' == missing)Again, looks (to me) from the checksums that the data partitions are OK.
root@Microknoppix:/home/knoppix# mdadm --examine /dev/sd[abcd][3] | grep -E "(^\/dev|UUID)"
/dev/sda3:
Array UUID : b697ee5c:dfd93286:04cbc712:c960ad5b
Device UUID : 1f2351ff:d6b0ce48:adc5d480:052a9385
/dev/sdb3:
Array UUID : b697ee5c:dfd93286:04cbc712:c960ad5b
Device UUID : ad97e3fa:7010280a:2013be33:8fa98bb2
/dev/sdc3:
Array UUID : b697ee5c:dfd93286:04cbc712:c960ad5b
Device UUID : 93aee45f:f0e48a25:1dc1448e:6956f9cc
/dev/sdd3:
Array UUID : b697ee5c:dfd93286:04cbc712:c960ad5b
Device UUID : e533daef:44960cd1:62926d25:0a6a4aa8
root@Microknoppix:/home/knoppix#The array UUID's are the same.
However, trying to assemble the data array:
root@Microknoppix:/home/knoppix# mdadm --assemble /dev/md2 --verbose /dev/sd[abcd]3 mdadm: looking for devices for /dev/md2 mdadm: /dev/sda3 is identified as a member of /dev/md2, slot 0. mdadm: /dev/sdb3 is identified as a member of /dev/md2, slot 1. mdadm: /dev/sdc3 is identified as a member of /dev/md2, slot 2. mdadm: /dev/sdd3 is identified as a member of /dev/md2, slot 3. mdadm: failed to add /dev/sdb3 to /dev/md2: Invalid argument mdadm: failed to add /dev/sdc3 to /dev/md2: Invalid argument mdadm: failed to add /dev/sdd3 to /dev/md2: Invalid argument mdadm: failed to add /dev/sda3 to /dev/md2: Invalid argument mdadm: /dev/md2 assembled from 0 drives - need all 4 to start it (use --run to insist).
and finally with --run:
root@Microknoppix:/home/knoppix# mdadm --assemble /dev/md2 --run --verbose /dev/sd[abcd]3 mdadm: looking for devices for /dev/md2 mdadm: /dev/sda3 is identified as a member of /dev/md2, slot 0. mdadm: /dev/sdb3 is identified as a member of /dev/md2, slot 1. mdadm: /dev/sdc3 is identified as a member of /dev/md2, slot 2. mdadm: /dev/sdd3 is identified as a member of /dev/md2, slot 3. mdadm: failed to add /dev/sdb3 to /dev/md2: Invalid argument mdadm: failed to add /dev/sdc3 to /dev/md2: Invalid argument mdadm: failed to add /dev/sdd3 to /dev/md2: Invalid argument mdadm: failed to add /dev/sda3 to /dev/md2: Invalid argument mdadm: failed to RUN_ARRAY /dev/md2: Invalid argument
I tried also with /dev/md0, but this lead to the same result.
Deleting /etc/mdadm/mdadm.conf also didn't fix it.
Can anyone shine a light on this? I suppose using mdadm --create will cause the array to build from scratch and that'll be the end of it, so I didn't try that...
8 Replies
Replies have been turned off for this discussion
You could try forcing the array online but you may wish to clone your disks first. If you coyountact support you could purchase a data recovery attempt where support would attempt to recover your data.
What is the SMART stats of your disks like?
Edit: Oops. I confused the creation time with the update time.
Before you try forcing it to start, what is the output of the following?
# cat /proc/partitions
# for i in /dev/sd[a-z]; do echo $i; smartctl -a $i | egrep "Model|Firm|Sector|Hours|Error|Uncorr"; done;I guess the SMART stats are OK, the disks have been 'on power' for only about 300 hours (bought them in the beginning of August). Last time I looked at SMART data (via OS6 interface) was around 170 hours, no errors then.
How would I force the array online?
Data recovery by Netgear is not an option I guess (fiddled aroud too much (OS4<->OS6), plus the Pro they were in was not bought new).
Next to that, the data is not that valuable (missing it would be an inconvenience, but not a real problem).
I don't have the spare space to clone about 16 TB. And my girlfriend won't make me live to the end of the weekend if I spend another 1000 EURO's for new disks ... :smileyfrustrated:
So I'll take the chances losing the data.
The disks are now in a Pro6 running Knoppix.
The requested output:
root@Microknoppix:/home/knoppix# cat /proc/partitions major minor #blocks name 240 0 10559232 cloop0 252 0 2259732 zram0 8 0 5860522584 sda 8 1 4193272 sda1 8 2 524228 sda2 8 3 5855800708 sda3 8 16 5860522584 sdb 8 17 4193272 sdb1 8 18 524228 sdb2 8 19 5855800708 sdb3 8 32 5860522584 sdc 8 33 4193272 sdc1 8 34 524228 sdc2 8 35 5855800708 sdc3 8 48 5860522584 sdd 8 49 4193272 sdd1 8 50 524228 sdd2 8 51 5855800708 sdd3 8 80 122368 sdf 8 81 122250 sdf1 8 64 7566624 sde 8 65 4556800 sde1 8 66 3008512 sde2
sda,b,c,d are HDD's,
sde is Knoppix pendrive
sdf is internal flash (I presume)
root@Microknoppix:/home/knoppix# for i in /dev/sd[a-z]; do echo $i; smartctl -a $i | egrep "Model|Firm|Sector|Hours|Error|Uncorr"; done; /dev/sda Device Model: WDC WD60EFRX-68MYMN1 Firmware Version: 82.00A82 Sector Sizes: 512 bytes logical, 4096 bytes physical Error logging capability: (0x01) Error logging supported. SCT Error Recovery Control supported. 1 Raw_Read_Error_Rate 0x002f 200 200 051 Pre-fail Always - 0 5 Reallocated_Sector_Ct 0x0033 200 200 140 Pre-fail Always - 0 7 Seek_Error_Rate 0x002e 100 253 000 Old_age Always - 0 9 Power_On_Hours 0x0032 100 100 000 Old_age Always - 288 197 Current_Pending_Sector 0x0032 200 200 000 Old_age Always - 0 198 Offline_Uncorrectable 0x0030 100 253 000 Old_age Offline - 0 199 UDMA_CRC_Error_Count 0x0032 200 200 000 Old_age Always - 0 200 Multi_Zone_Error_Rate 0x0008 100 253 000 Old_age Offline - 0 SMART Error Log Version: 1 No Errors Logged /dev/sdb Device Model: WDC WD60EFRX-68MYMN1 Firmware Version: 82.00A82 Sector Sizes: 512 bytes logical, 4096 bytes physical Error logging capability: (0x01) Error logging supported. SCT Error Recovery Control supported. 1 Raw_Read_Error_Rate 0x002f 200 200 051 Pre-fail Always - 0 5 Reallocated_Sector_Ct 0x0033 200 200 140 Pre-fail Always - 0 7 Seek_Error_Rate 0x002e 100 253 000 Old_age Always - 0 9 Power_On_Hours 0x0032 100 100 000 Old_age Always - 288 197 Current_Pending_Sector 0x0032 200 200 000 Old_age Always - 0 198 Offline_Uncorrectable 0x0030 100 253 000 Old_age Offline - 0 199 UDMA_CRC_Error_Count 0x0032 200 200 000 Old_age Always - 0 200 Multi_Zone_Error_Rate 0x0008 100 253 000 Old_age Offline - 0 SMART Error Log Version: 1 No Errors Logged /dev/sdc Device Model: WDC WD60EFRX-68MYMN1 Firmware Version: 82.00A82 Sector Sizes: 512 bytes logical, 4096 bytes physical Error logging capability: (0x01) Error logging supported. SCT Error Recovery Control supported. 1 Raw_Read_Error_Rate 0x002f 200 200 051 Pre-fail Always - 0 5 Reallocated_Sector_Ct 0x0033 200 200 140 Pre-fail Always - 0 7 Seek_Error_Rate 0x002e 100 253 000 Old_age Always - 0 9 Power_On_Hours 0x0032 100 100 000 Old_age Always - 288 197 Current_Pending_Sector 0x0032 200 200 000 Old_age Always - 0 198 Offline_Uncorrectable 0x0030 100 253 000 Old_age Offline - 0 199 UDMA_CRC_Error_Count 0x0032 200 200 000 Old_age Always - 0 200 Multi_Zone_Error_Rate 0x0008 100 253 000 Old_age Offline - 0 SMART Error Log Version: 1 No Errors Logged /dev/sdd Device Model: WDC WD60EFRX-68MYMN1 Firmware Version: 82.00A82 Sector Sizes: 512 bytes logical, 4096 bytes physical Error logging capability: (0x01) Error logging supported. SCT Error Recovery Control supported. 1 Raw_Read_Error_Rate 0x002f 200 200 051 Pre-fail Always - 0 5 Reallocated_Sector_Ct 0x0033 200 200 140 Pre-fail Always - 0 7 Seek_Error_Rate 0x002e 200 200 000 Old_age Always - 0 9 Power_On_Hours 0x0032 100 100 000 Old_age Always - 294 197 Current_Pending_Sector 0x0032 200 200 000 Old_age Always - 0 198 Offline_Uncorrectable 0x0030 100 253 000 Old_age Offline - 0 199 UDMA_CRC_Error_Count 0x0032 200 200 000 Old_age Always - 0 200 Multi_Zone_Error_Rate 0x0008 100 253 000 Old_age Offline - 0 SMART Error Log Version: 1 No Errors Logged /dev/sde /dev/sdf /dev/sdg /dev/sdhIf it is OS6 then it would be /dev/md127 not /dev/md2
Does it make any difference if you try to assemble md127 rather than md2?Best to leave forcing it online as a last resort.
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