Hi there,
I´m pretty new here and already tried finding a solution with aunt
google - without luck. So hopefully someone of you can help me:
I´m running a NAS with 4x 12TB WD120EFAX using mdadm Raid5 on the basis
of Debian 10.
Because of capacity and speed I tried adding another WD120EFAX by simply
"mdadm --grow --raid-devices=5 /dev/md0 /dev/sd[a-e]1
--backup-file=/tmp/bu.bak"
Everything worked... but during reshape, I had a power interruption.
When power was back, I tried to restart NAS but the md disappeared.
Long story short... after asking aunt Google I managed to get the raid5
up "active, not started":
root@nas:~# mdadm -D /dev/md0
/dev/md0:
Version : 1.2
Creation Time : Sun May 17 00:23:42 2020
Raid Level : raid5
Used Dev Size : 18446744073709551615
Raid Devices : 5
Total Devices : 5
Persistence : Superblock is persistent
Update Time : Mon May 25 16:05:38 2020
State : active, Not Started
Active Devices : 5
Working Devices : 5
Failed Devices : 0
Spare Devices : 0
Layout : left-symmetric
Chunk Size : 512K
Delta Devices : 1, (4->5)
Name : nas:0 (local to host nas)
UUID : d7d800b3:d203ff93:9cc2149a:804a1b97
Events : 38602
Number Major Minor RaidDevice State
0 8 1 0 active sync /dev/sda1
1 8 17 1 active sync /dev/sdb1
2 8 33 2 active sync /dev/sdc1
4 8 49 3 active sync /dev/sdd1
5 8 65 4 active sync /dev/sde1
I already tried to repair the md0 using the mentioned way from
https://serverfault.com/questions/776170/mdadm-grow-power-failure-dev-md2-no-longer-detected-raid5
... however, the raid didn´t start.
Unfortunately the raid is not mountable (cannot read superblock), even
readonly. So it´s impossible to run a backup of stored data, for now.
Any help is highly appreciated.
Greetings
Thomas
