我正在尝试从 MyBookLiveDuo 3TB*2 RAID1 设置恢复数据，该设置不响应 http/ssh 访问。我从机箱中取出一个驱动器，并通过 SATA 将其连接到一台 Linux 笔记本电脑。我已经运行了以下内容。
dmesg 说它是 /dev/sdc：
[125141.929807] ata4: exception Emask 0x10 SAct 0x0 SErr 0x4040000 action 0xe frozen
[125141.929811] ata4: irq_stat 0x00000040, connection status changed
[125141.929813] ata4: SError: { CommWake DevExch }
[125141.929827] ata4: hard resetting link
[125147.695101] ata4: link is slow to respond, please be patient (ready=0)
[125151.729658] ata4: SATA link up 1.5 Gbps (SStatus 113 SControl 300)
[125151.909228] ata4.00: ATA-9: WDC WD30EZRX-00D8PB0, 80.00A80, max UDMA/133
[125151.909231] ata4.00: 5860533168 sectors, multi 0: LBA48 NCQ (depth 31/32), AA
[125151.909888] ata4.00: configured for UDMA/133
[125151.925597] ata4: EH complete
[125151.925652] scsi 3:0:0:0: Direct-Access ATA WDC WD30EZRX-00D 0A80 PQ: 0 ANSI: 5
[125151.925828] sd 3:0:0:0: [sdc] 5860533168 512-byte logical blocks: (3.00 TB/2.72 TiB)
[125151.925830] sd 3:0:0:0: [sdc] 4096-byte physical blocks
[125151.925833] sd 3:0:0:0: Attached scsi generic sg2 type 0
[125151.925971] sd 3:0:0:0: [sdc] Write Protect is off
[125151.925973] sd 3:0:0:0: [sdc] Mode Sense: 00 3a 00 00
[125151.925995] sd 3:0:0:0: [sdc] Write cache: enabled, read cache: enabled, doesn't support DPO or FUA
[125152.002603] sdc: sdc1 sdc2 sdc3 sdc4
[125152.003134] sd 3:0:0:0: [sdc] Attached SCSI disk
[125152.220477] md: bind<sdc4>
[125152.232731] md: bind<sdc3>
[125152.233892] md/raid1:md126: active with 1 out of 2 mirrors
[125152.233912] md126: detected capacity change from 0 to 512741376
[125152.234269] md126: unknown partition table
尝试直接挂载 sdc4 不起作用：
$ sudo mount /dev/sdc4 /home/xxx/wdc -t auto
mount: unknown filesystem type 'linux_raid_member'
Mdstat 仅显示 sdc3 为活动状态，但 sdc4 为非活动状态：
$ 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>
Parted 显示 sdc4 缺少文件系统：
$ 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
Gdisk“v”（验证）没有发现任何问题：
$ sudo gdisk /dev/sdc
GPT fdisk (gdisk) version 0.8.8
Partition table scan:
MBR: protective
BSD: not present
APM: not present
GPT: present
Found valid GPT with protective MBR; using GPT.
Command (? for help): p
Disk /dev/sdc: 5860533168 sectors, 2.7 TiB
Logical sector size: 512 bytes
Disk identifier (GUID): FA502922-25C1-4759-AAF8-3D1DDA73F5C4
Partition table holds up to 128 entries
First usable sector is 34, last usable sector is 5860533134
Partitions will be aligned on 2048-sector boundaries
Total free space is 31597 sectors (15.4 MiB)
Number Start (sector) End (sector) Size Code Name
1 1032192 5031935 1.9 GiB FD00 primary
2 5031936 9031679 1.9 GiB FD00 primary
3 30720 1032191 489.0 MiB FD00 primary
4 9031680 5860532223 2.7 TiB FD00 primary
Command (? for help): v
No problems found. 31597 free sectors (15.4 MiB) available in 2
segments, the largest of which is 30686 (15.0 MiB) in size.
Command (? for help): q
尝试组装和扫描仅显示 /dev/sdc3 处于活动状态：
$ 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>
E2fsck 在超级块中显示错误的幻数：
$ sudo e2fsck /dev/sdc3
e2fsck 1.42.9 (4-Feb-2014)
/dev/sdc3 is in use.
e2fsck: Cannot continue, aborting.
$ sudo e2fsck /dev/sdc4
e2fsck 1.42.9 (4-Feb-2014)
ext2fs_open2: Bad magic number in super-block
e2fsck: Superblock invalid, trying backup blocks...
e2fsck: Bad magic number in super-block while trying to open /dev/sdc4
The superblock could not be read or does not describe a valid ext2/ext3/ext4
filesystem. If the device is valid and it really contains an ext2/ext3/ext4
filesystem (and not swap or ufs or something else), then the superblock
is corrupt, and you might try running e2fsck with an alternate superblock:
e2fsck -b 8193 <device>
or
e2fsck -b 32768 <device>
$
尝试挂载 md127 认为它是 NTFS ？？？
$ sudo mount /dev/md127 /home/xxx/wdc -t auto
NTFS signature is missing.
Failed to mount '/dev/md127': Invalid argument
The device '/dev/md127' doesn't seem to have a valid NTFS.
Maybe the wrong device is used? Or the whole disk instead of a
partition (e.g. /dev/sda, not /dev/sda1)? Or the other way around?
关于如何进一步安装 /dev/sdc4 并恢复数据有什么建议吗？
编辑1： 检查 sdc4 的输出如下。它表示 RAID 级别 = 线性。
$ 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)
检查 sdc3 的输出如下，mdstat 表示该输出处于活动状态。它表示 RAID 级别 = 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>
分区是：
$ 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
编辑 2：（来自另一个机箱的不同 RAID 磁盘）
使用来自不同 WDLiveDuo 机箱的良好磁盘，以相同 RAID1 方式配置（2*3TB 磁盘），检查 sdc3 和 sdc4 的输出显示两者的 RAID 级别 = RAID1。因此，对于列出的坏磁盘多于，sdc3 显示正确的 RAID 级别 = RAID1，但不知何故，sdc4 没有配置正确的 RAID 级别。有没有办法将 RAID 级别更改/修复为 RAID1，然后它允许我加载它并从坏磁盘中获取数据？
$ cat /proc/mdstat
Personalities : [linear] [multipath] [raid0] [raid1] [raid6] [raid5] [raid4] [raid10]
md126 : inactive sdc4[2](S)
2925750136 blocks super 1.0
md127 : inactive sdc3[1](S)
500724 blocks super 1.0
unused devices: <none>
$
$ 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
$
$ 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 : e0963cfc:7ba16214:94e24c90:32988d39
Update Time : Mon Jul 4 13:20:48 2016
Checksum : 412bab99 - correct
Events : 288
Device Role : Active device 1
Array State : AA ('A' == active, '.' == missing)
$
$ sudo mdadm --examine /dev/sdc4
/dev/sdc4:
Magic : a92b4efc
Version : 1.0
Feature Map : 0x0
Array UUID : ac48cc98:1d450838:dd0b0364:61b3168e
Name : MyBookLiveDuo:3
Creation Time : Sat Jul 2 19:57:43 2016
Raid Level : raid1
Raid Devices : 2
Avail Dev Size : 5851500272 (2790.21 GiB 2995.97 GB)
Array Size : 2925750136 (2790.21 GiB 2995.97 GB)
Super Offset : 5851500528 sectors
State : clean
Device UUID : 1233b655:2f5fd745:c1c71658:f05af045
Update Time : Mon Jul 4 13:21:15 2016
Checksum : b83b08dc - correct
Events : 54432
Device Role : Active device 1
Array State : AA ('A' == active, '.' == missing)
$
$ sudo mdadm --stop /dev/md12[567]
mdadm: stopped /dev/md126
mdadm: stopped /dev/md127
$
$ sudo mdadm --assemble --scan
mdadm: /dev/md/MyBookLiveDuo:3 has been started with 1 drive (out of 2).
mdadm: /dev/md/MyBookLiveDuo:2 has been started with 1 drive (out of 2).
$
$ cat /proc/mdstat
Personalities : [linear] [multipath] [raid0] [raid1] [raid6] [raid5] [raid4] [raid10]
md126 : active raid1 sdc3[1]
500724 blocks super 1.0 [2/1] [_U]
md127 : active raid1 sdc4[2]
2925750136 blocks super 1.0 [2/1] [_U]
unused devices: <none>
$
$ sudo parted -l /dev/sdc
Model: ATA WDC WD30EFRX-68E (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 ext4 primary raid
Error: /dev/md126: unrecognised disk label
Model: Linux Software RAID Array (md)
Disk /dev/md127: 2996GB
Sector size (logical/physical): 512B/4096B
Partition Table: loop
Number Start End Size File system Flags
1 0.00B 2996GB 2996GB ext4
$
$ sudo gdisk /dev/sdc
GPT fdisk (gdisk) version 0.8.8
Partition table scan:
MBR: protective
BSD: not present
APM: not present
GPT: present
Found valid GPT with protective MBR; using GPT.
Command (? for help): p
Disk /dev/sdc: 5860533168 sectors, 2.7 TiB
Logical sector size: 512 bytes
Disk identifier (GUID): BDE03D26-EB85-4348-A4E0-A229FC01EE93
Partition table holds up to 128 entries
First usable sector is 34, last usable sector is 5860533134
Partitions will be aligned on 2048-sector boundaries
Total free space is 31597 sectors (15.4 MiB)
Number Start (sector) End (sector) Size Code Name
1 1032192 5031935 1.9 GiB FD00 primary
2 5031936 9031679 1.9 GiB FD00 primary
3 30720 1032191 489.0 MiB FD00 primary
4 9031680 5860532223 2.7 TiB FD00 primary
Command (? for help): v
No problems found. 31597 free sectors (15.4 MiB) available in 2
segments, the largest of which is 30686 (15.0 MiB) in size.
Command (? for help): q
$
$ sudo mount /dev/md127 /home/xxx/wdc -t ext4
mount: wrong fs type, bad option, bad superblock on /dev/md127,
missing codepage or helper program, or other error
In some cases useful info is found in syslog - try
dmesg | tail or so
答案1
输出mdadm --examine /dev/sdc4显示了 raid 设备未上线的原因：
Raid Level : linear
线性 RAID 设备需要 RAID 组中的所有设备都能够启动。
https://raid.wiki.kernel.org/index.php/RAID_setup#Linear_mode