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... 😉
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 --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...
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.
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 ...
root@Microknoppix:/home/knoppix# mdadm --assemble /dev/md127 --verbose /dev/sd[abcd]3
mdadm: looking for devices for /dev/md127
mdadm: /dev/sda3 is identified as a member of /dev/md127, slot 0.
mdadm: /dev/sdb3 is identified as a member of /dev/md127, slot 1.
mdadm: /dev/sdc3 is identified as a member of /dev/md127, slot 2.
mdadm: /dev/sdd3 is identified as a member of /dev/md127, slot 3.
mdadm: failed to add /dev/sdb3 to /dev/md127: Invalid argument
mdadm: failed to add /dev/sdc3 to /dev/md127: Invalid argument
mdadm: failed to add /dev/sdd3 to /dev/md127: Invalid argument
mdadm: failed to add /dev/sda3 to /dev/md127: Invalid argument
mdadm: /dev/md127 assembled from 0 drives - need all 4 to start it (use --run to insist).
The array was created with OS4, but there was the stupidity with the switching as described in the post I referenced in the TS, which caused parts of OS6 landing on the OS4 partition.
Therefore I'd rather not put it back on Readynas OS (4 / 6), because I don't trust what drama will happen (and it probably won't boot anyway).
I suspect even the forced assemble will not work, as I (with limited knowledge) see no reason why the non-forced assembling doesn't work, as the RAID events have exactly the same value (99) on all disks.
I'm therefore open to suggestions from more experienced RAID builders 😉
I know I and only I am responsible for whatever consequences, I won't hold anyone (nor Netgear) responsible for what happens or when the array goes exit. I'm just looking for advice and experience from users more experienced than I am.
One thing I did notice: in a 'regular Netgear' setup, there are symbolic links (system running 4.2.27):
