NAS540: Volume down, no option to repair

Mijzelf

Right. Your second disk is dead, I'm afraid, but the remaining disks should be enough to rebuild the array (degraded). Unfortunately you disk sdd3 has lost it's device role, it's now 'spare', but assuming the disks are in the same physical position as when you created the array, I assume that should be 'Active device 3'.

In that case the command to re-build the array is

mdadm --stop /dev/md2

mdadm --create --assume-clean --level=5 --raid-devices=4 --metadata=1.2 --chunk=64K --layout=left-symmetric --bitmap=none /dev/md2 /dev/sda3 missing /dev/sdc3 /dev/sdd3

That are two lines, each starting with mdadm. I don't dare to put it in code tags, as this forum is acting strange.

When your array is up again, you can pull the second disk, and put a new disk in to get it healthy again.

hola

Thank you for the great assistance.

mdadm --create --assume-clean --level=5 --raid-devices=4 --metadata=1.2 --chunk=64K --layout=left-symmetric --bitmap=none /dev/md2 /dev/sda3 missing /dev/sdc3 /dev/sdd3
I got the error, it said need to use --grow?

Mijzelf

Omit the --bitmap=none

katas

I encountered the similar problem on my NAS540 with RAID 6.
Can somebody help me to solve it?

# cat /proc/mdstat
Personalities : [linear] [raid0] [raid1] [raid10] [raid6] [raid5] [raid4]
md1 : active raid1 sda2[0] sdc2[5] sdd2[6] sdb2[4]
1998784 blocks super 1.2 [4/4] [UUUU]

md0 : active raid1 sda1[0] sdc1[5] sdd1[6] sdb1[4]
1997760 blocks super 1.2 [4/4] [UUUU]

# cat /proc/partitions

major minor #blocks name

7 0 147456 loop0

31 0 256 mtdblock0

31 1 512 mtdblock1

31 2 256 mtdblock2

31 3 10240 mtdblock3

31 4 10240 mtdblock4

31 5 112640 mtdblock5

31 6 10240 mtdblock6

31 7 112640 mtdblock7

31 8 6144 mtdblock8

8 0 5860522584 sda

8 1 1998848 sda1

8 2 1999872 sda2

8 3 5856522240 sda3

8 16 5860522584 sdb

8 17 1998848 sdb1

8 18 1999872 sdb2

8 19 5856522240 sdb3

8 32 5860522584 sdc

8 33 1998848 sdc1

8 34 1999872 sdc2

8 35 5856522240 sdc3

8 48 5860522584 sdd

8 49 1998848 sdd1

8 50 1999872 sdd2

8 51 5856522240 sdd3

31 9 102424 mtdblock9

9 0 1997760 md0

9 1 1998784 md1

31 10 4464 mtdblock10

# mdadm --examine /dev/sd[abcd]3

/dev/sda3:

Magic : a92b4efc

Version : 1.2

Feature Map : 0x4

Array UUID : a8c78b8e:4ab1fe37:160fd540:b7a8cd63

Name : NAS540:2 (local to host NAS540)

Creation Time : Sat Dec 14 05:08:13 2019

Raid Level : raid6

Raid Devices : 4

Avail Dev Size : 11712782336 (5585.09 GiB 5996.94 GB)

Array Size : 11712781952 (11170.18 GiB 11993.89 GB)

Used Dev Size : 11712781952 (5585.09 GiB 5996.94 GB)

Data Offset : 262144 sectors

Super Offset : 8 sectors

State : clean

Device UUID : 57579709:2a1053f9:4e0e390f:bcef6466

Reshape pos'n : 7602176000 (7250.00 GiB 7784.63 GB)

New Layout : left-symmetric

Update Time : Sat Dec 21 05:08:45 2019

Checksum : aeda0bb6 - correct

Events : 2801362

Layout : left-symmetric-6

Chunk Size : 64K

Device Role : Active device 0

Array State : AAAA ('A' == active, '.' == missing)

/dev/sdb3:

Magic : a92b4efc

Version : 1.2

Feature Map : 0x4

Array UUID : a8c78b8e:4ab1fe37:160fd540:b7a8cd63

Name : NAS540:2 (local to host NAS540)

Creation Time : Sat Dec 14 05:08:13 2019

Raid Level : raid6

Raid Devices : 4

Avail Dev Size : 11712782336 (5585.09 GiB 5996.94 GB)

Array Size : 11712781952 (11170.18 GiB 11993.89 GB)

Used Dev Size : 11712781952 (5585.09 GiB 5996.94 GB)

Data Offset : 262144 sectors

Super Offset : 8 sectors

State : active

Device UUID : 27e3c53c:450be072:4b3e069c:247f1661

Reshape pos'n : 7602176000 (7250.00 GiB 7784.63 GB)

New Layout : left-symmetric

Update Time : Sat Dec 21 05:08:45 2019

Checksum : e3145207 - correct

Events : 2801362

Layout : left-symmetric-6

Chunk Size : 64K

Device Role : Active device 1

Array State : AAAA ('A' == active, '.' == missing)

/dev/sdc3:

Magic : a92b4efc

Version : 1.2

Feature Map : 0x4

Array UUID : a8c78b8e:4ab1fe37:160fd540:b7a8cd63

Name : NAS540:2 (local to host NAS540)

Creation Time : Sat Dec 14 05:08:13 2019

Raid Level : raid6

Raid Devices : 4

Avail Dev Size : 11712782336 (5585.09 GiB 5996.94 GB)

Array Size : 11712781952 (11170.18 GiB 11993.89 GB)

Used Dev Size : 11712781952 (5585.09 GiB 5996.94 GB)

Data Offset : 262144 sectors

Super Offset : 8 sectors

State : active

Device UUID : af400f15:def9e284:5c8da320:6b6f1d92

Reshape pos'n : 7602176000 (7250.00 GiB 7784.63 GB)

New Layout : left-symmetric

Update Time : Sat Dec 21 05:08:45 2019

Checksum : 8304dd81 - correct

Events : 2801362

Layout : left-symmetric-6

Chunk Size : 64K

Device Role : Active device 2

Array State : AAAA ('A' == active, '.' == missing)

/dev/sdd3:

Magic : a92b4efc

Version : 1.2

Feature Map : 0x6

Array UUID : a8c78b8e:4ab1fe37:160fd540:b7a8cd63

Name : NAS540:2 (local to host NAS540)

Creation Time : Sat Dec 14 05:08:13 2019

Raid Level : raid6

Raid Devices : 4

Avail Dev Size : 11712782336 (5585.09 GiB 5996.94 GB)

Array Size : 11712781952 (11170.18 GiB 11993.89 GB)

Used Dev Size : 11712781952 (5585.09 GiB 5996.94 GB)

Data Offset : 262144 sectors

Super Offset : 8 sectors

Recovery Offset : 7602176000 sectors

State : active

Device UUID : 4e2d4e04:9660ec5a:0a69bd17:d20c07ef

Reshape pos'n : 7602176000 (7250.00 GiB 7784.63 GB)

New Layout : left-symmetric

Update Time : Sat Dec 21 05:08:45 2019

Checksum : 6170a9f2 - correct

Events : 2801362

Layout : left-symmetric-6

Chunk Size : 64K

Device Role : Active device 3

Array State : AAAA ('A' == active, '.' == missing)

Mijzelf

What happens if you try to assemble it?

su

mdadm --assemble /dev/md2 /dev/sd[abcd]3

katas

Thank you for your reply. @Mijzelf
I still have the problem after tried to assemble my NAS540 via command.

# mdadm --assemble /dev/md2 /dev/sd[abcd]3

mdadm: Failed to restore critical section for reshape, sorry.
Possibly you needed to specify the --backup-file

What should I do next?
Do you know what would be the locations of the 'raid-file/backup' holding the configuration on the system?

Mijzelf

what would be the locations of the 'raid-file/backup'

I don't think such a file exists. But if it exists, it is in /firmware/mnt/sysdisk/, /firmware/mnt/nand/ or /etc/zyxel/, being the only storage pools outside your data array. The latter 2 are in flash memory.

Your array was 'reshaping', and is stalled around 70%. Wat exactly was you doing?

katas

Your array was 'reshaping', and is stalled around 70%. Wat exactly was you doing?

Don't know. What else can I do?

Mijzelf

Have you checked the locations I gave you?

You don't know what you were doing. So this problem came out of the blue? Is it as far as you know possible that one disk was dropped from the array, and automatically added again? On raid5 that would look different, but unfortunately I have no experience with raid6 problems.