Hi
I have a WD Live duo setup with two 3TB drives in RAID1. After a recent power surge etc, I could not access the enclosure data. I removed the drives out from the enclosure and connected them via esata cable to a Linux laptop. One of the drives had physical noise and failed to connect at all. The other drive was able to connect and showed up as /dev/sdc. Following some online search, I issued the following commands to get some results, but am unable to mount the drive to a linux laptop via esata. Questions:
* Ideally both sdc3 and sdc4 should have shown RAID=RAID1. If sdc4 is showing RAID=linear, is it because the other drive went totally bad, and software decided to reconfigure this drive from RAID1 to linear ?
* Given the one of the two drives is totally dead, is it still possible to reconfigure, mount and recover data from the single drive?
* I tried scanning the drive via r-linux and it does show files exist, but does not show any folder information. So data is there on the drive. Is there a way to recreate the setup with just this single drive, so that I can extract files with folder information?
* Looking at an online "derrick" script, the script seems to call mdadm create with the "missing" flag. Is that something I should be doing to be able to assemble and recover data from the drive ?
"mdadm --create $rootfsRaid --verbose --metadata=0.9 --raid-devices=2 --level=raid1 --run $diskRoot1 missing"
Thanks
Amit
Parted shows missing filesystem for sdc4 :
$ sudo parted -l
Model: ATA WDC WD30EZRX-00D (scsi)
Disk /dev/sdc: 3001GB
Sector size (logical/physical): 512B/4096B
Partition Table: gpt
Number Start End Size File system Name Flags
3 15.7MB 528MB 513MB primary raid
1 528MB 2576MB 2048MB ext3 primary raid
2 2576MB 4624MB 2048MB ext3 primary raid
4 4624MB 3001GB 2996GB primary raid
Mdstat shows only sdc3 as active, but sdc4 as inactive:
$ sudo cat /proc/mdstat
Personalities : [linear] [raid1]
md126 : active (auto-read-only) raid1 sdc3[2]
500724 blocks super 1.0 [2/1] [_U]
md127 : inactive sdc4[0](S)
2925750264 blocks super 1.0
unused devices: <none>
Trying to assemble and scan only shows /dev/sdc3 as active:
$ sudo mdadm --stop /dev/md12[567]
mdadm: stopped /dev/md126
mdadm: stopped /dev/md127
$ sudo cat /proc/mdstat
Personalities : [linear] [raid1]
unused devices: <none>
$ sudo mdadm --assemble --scan
mdadm: /dev/md/MyBookLiveDuo:3 assembled from 1 drive - not enough to start the array.
mdadm: /dev/md/MyBookLiveDuo:2 has been started with 1 drive (out of 2).
mdadm: /dev/md/MyBookLiveDuo:3 assembled from 1 drive - not enough to start the array.
$ sudo cat /proc/mdstat
Personalities : [linear] [raid1]
md127 : active raid1 sdc3[2]
500724 blocks super 1.0 [2/1] [_U]
unused devices: <none>
Output from examine sdc3 is below, which mdstat says is active. It says RAID level = RAID1.
$ sudo mdadm --examine /dev/sdc3
/dev/sdc3:
Magic : a92b4efc
Version : 1.0
Feature Map : 0x0
Array UUID : 7c040c5e:9c30ac6d:e534a129:20457e22
Name : MyBookLiveDuo:2
Creation Time : Wed Dec 31 19:01:40 1969
Raid Level : raid1
Raid Devices : 2
Avail Dev Size : 1001448 (489.07 MiB 512.74 MB)
Array Size : 500724 (489.07 MiB 512.74 MB)
Super Offset : 1001456 sectors
State : clean
Device UUID : 1d9fe3e3:d5ac7387:d9ededba:88ca24a5
Update Time : Sun Jul 3 11:53:31 2016
Checksum : 31589560 - correct
Events : 101
Device Role : Active device 1
Array State : .A ('A' == active, '.' == missing)
$ cat /proc/mdstat
Personalities : [linear] [multipath] [raid0] [raid1] [raid6] [raid5] [raid4] [raid10]
md126 : active (auto-read-only) raid1 sdc3[2]
500724 blocks super 1.0 [2/1] [_U]
md127 : inactive sdc4[0](S)
2925750264 blocks super 1.0
unused devices: <none>
But, output from examine sdc4 is below, which says RAID level = linear.
$ sudo mdadm --examine /dev/sdc4
/dev/sdc4:
Magic : a92b4efc
Version : 1.0
Feature Map : 0x0
Array UUID : 374e689e:3bfd050c:ab0b0dce:2d50f5fd
Name : MyBookLiveDuo:3
Creation Time : Mon Sep 16 14:53:47 2013
Raid Level : linear
Raid Devices : 2
Avail Dev Size : 5851500528 (2790.21 GiB 2995.97 GB)
Used Dev Size : 0
Super Offset : 5851500528 sectors
State : clean
Device UUID : 9096f74b:0a8f2b61:93347be3:6d3b6c1b
Update Time : Mon Sep 16 14:53:47 2013
Checksum : 77aa5963 - correct
Events : 0
Rounding : 0K
Device Role : Active device 0
Array State : AA ('A' == active, '.' == missing)
And partitions output is:
$ cat /proc/partitions
major minor #blocks name
8 0 1953514584 sda
8 1 102400 sda1
8 2 1953411072 sda2
8 16 1953514584 sdb
8 17 248832 sdb1
8 18 1 sdb2
8 21 1953263616 sdb5
252 0 1953261568 dm-0
252 1 1919635456 dm-1
252 2 33488896 dm-2
8 32 2930266584 sdc
8 33 1999872 sdc1
8 34 1999872 sdc2
8 35 500736 sdc3
8 36 2925750272 sdc4
9 126 500724 md126
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