Recovering "inactive " RAID5 array
by jan128 from LinuxQuestions.org on (#59W26)
I have an "inactive " RAID5 array and I am unable to activate it.
I am attaching my latest series of attempts to do such activation.
I am basically lost and have no idea what to do next.
Any assistance would be greatly appreciated.
Code:f@f-SATA:~$ sudo mdadm /dev/md42
[sudo] password for f:
/dev/md42: raid5 8 devices, 0 spares. Use mdadm --detail for more detail.
f@f-SATA:~$ sudo mdadm -D /dev/md42
/dev/md42:
Version : 1.2
Creation Time : Thu Oct 15 09:50:58 2020
Raid Level : raid5
Used Dev Size : 2782208 (2.65 GiB 2.85 GB)
Raid Devices : 8
Total Devices : 6
Persistence : Superblock is persistent
Update Time : Fri Oct 30 18:43:39 2020
State : active, FAILED, Not Started
Active Devices : 6
Working Devices : 6
Failed Devices : 0
Spare Devices : 0
Layout : left-symmetric
Chunk Size : 512K
Name : a-SATA:42
UUID : fbe4babd:b3c28449:66d4881d:46391ff4
Events : 465
Number Major Minor RaidDevice State
0 8 161 0 active sync /dev/sdk1
1 8 162 1 active sync /dev/sdk2
4 8 164 2 active sync /dev/sdk4
8 259 16 3 active sync /dev/sdd22
7 259 15 4 active sync /dev/sdd21
6 259 14 5 active sync /dev/sdd20
12 0 0 12 removed
14 0 0 14 removed
f@f-SATA:~$ sudo mdadm -R /dev/md42
f@f-SATA:~$ sudo mdadm --run /dev/md42
f@f-SATA:~$ sudo mdadm --detail /dev/md42
/dev/md42:
Version : 1.2
Creation Time : Thu Oct 15 09:50:58 2020
Raid Level : raid5
Used Dev Size : 2782208 (2.65 GiB 2.85 GB)
Raid Devices : 8
Total Devices : 6
Persistence : Superblock is persistent
Update Time : Fri Oct 30 18:43:39 2020
State : active, FAILED, Not Started
Active Devices : 6
Working Devices : 6
Failed Devices : 0
Spare Devices : 0
Layout : left-symmetric
Chunk Size : 512K
Name : a-SATA:42
UUID : fbe4babd:b3c28449:66d4881d:46391ff4
Events : 465
Number Major Minor RaidDevice State
0 8 161 0 active sync /dev/sdk1
1 8 162 1 active sync /dev/sdk2
4 8 164 2 active sync /dev/sdk4
8 259 16 3 active sync /dev/sdd22
7 259 15 4 active sync /dev/sdd21
6 259 14 5 active sync /dev/sdd20
12 0 0 12 removed
14 0 0 14 removed
f@f-SATA:~$ sudo mdadm --stop /dev/md42
mdadm: stopped /dev/md42
f@f-SATA:~$ sudo mdadm --run /dev/md42
f@f-SATA:~$ sudo mdadm --detail /dev/md42
/dev/md42:
Version :
Raid Level : raid0
Total Devices : 0
State : inactive
Number Major Minor RaidDevice
f@f-SATA:~$ sudo mdadm --detail /dev/md42
/dev/md42:
Version :
Raid Level : raid0
Total Devices : 0
State : inactive
Number Major Minor RaidDevice
f@f-SATA:~$ sudo mdadm --assemble /dev/md42
mdadm: /dev/md42 assembled from 3 drives - not enough to start the array.
f@f-SATA:~$ sudo mdadm --detail /dev/md42
/dev/md42:
Version :
Raid Level : raid0
Total Devices : 0
State : inactive
Number Major Minor RaidDevice
f@f-SATA:~$


I am attaching my latest series of attempts to do such activation.
I am basically lost and have no idea what to do next.
Any assistance would be greatly appreciated.
Code:f@f-SATA:~$ sudo mdadm /dev/md42
[sudo] password for f:
/dev/md42: raid5 8 devices, 0 spares. Use mdadm --detail for more detail.
f@f-SATA:~$ sudo mdadm -D /dev/md42
/dev/md42:
Version : 1.2
Creation Time : Thu Oct 15 09:50:58 2020
Raid Level : raid5
Used Dev Size : 2782208 (2.65 GiB 2.85 GB)
Raid Devices : 8
Total Devices : 6
Persistence : Superblock is persistent
Update Time : Fri Oct 30 18:43:39 2020
State : active, FAILED, Not Started
Active Devices : 6
Working Devices : 6
Failed Devices : 0
Spare Devices : 0
Layout : left-symmetric
Chunk Size : 512K
Name : a-SATA:42
UUID : fbe4babd:b3c28449:66d4881d:46391ff4
Events : 465
Number Major Minor RaidDevice State
0 8 161 0 active sync /dev/sdk1
1 8 162 1 active sync /dev/sdk2
4 8 164 2 active sync /dev/sdk4
8 259 16 3 active sync /dev/sdd22
7 259 15 4 active sync /dev/sdd21
6 259 14 5 active sync /dev/sdd20
12 0 0 12 removed
14 0 0 14 removed
f@f-SATA:~$ sudo mdadm -R /dev/md42
f@f-SATA:~$ sudo mdadm --run /dev/md42
f@f-SATA:~$ sudo mdadm --detail /dev/md42
/dev/md42:
Version : 1.2
Creation Time : Thu Oct 15 09:50:58 2020
Raid Level : raid5
Used Dev Size : 2782208 (2.65 GiB 2.85 GB)
Raid Devices : 8
Total Devices : 6
Persistence : Superblock is persistent
Update Time : Fri Oct 30 18:43:39 2020
State : active, FAILED, Not Started
Active Devices : 6
Working Devices : 6
Failed Devices : 0
Spare Devices : 0
Layout : left-symmetric
Chunk Size : 512K
Name : a-SATA:42
UUID : fbe4babd:b3c28449:66d4881d:46391ff4
Events : 465
Number Major Minor RaidDevice State
0 8 161 0 active sync /dev/sdk1
1 8 162 1 active sync /dev/sdk2
4 8 164 2 active sync /dev/sdk4
8 259 16 3 active sync /dev/sdd22
7 259 15 4 active sync /dev/sdd21
6 259 14 5 active sync /dev/sdd20
12 0 0 12 removed
14 0 0 14 removed
f@f-SATA:~$ sudo mdadm --stop /dev/md42
mdadm: stopped /dev/md42
f@f-SATA:~$ sudo mdadm --run /dev/md42
f@f-SATA:~$ sudo mdadm --detail /dev/md42
/dev/md42:
Version :
Raid Level : raid0
Total Devices : 0
State : inactive
Number Major Minor RaidDevice
f@f-SATA:~$ sudo mdadm --detail /dev/md42
/dev/md42:
Version :
Raid Level : raid0
Total Devices : 0
State : inactive
Number Major Minor RaidDevice
f@f-SATA:~$ sudo mdadm --assemble /dev/md42
mdadm: /dev/md42 assembled from 3 drives - not enough to start the array.
f@f-SATA:~$ sudo mdadm --detail /dev/md42
/dev/md42:
Version :
Raid Level : raid0
Total Devices : 0
State : inactive
Number Major Minor RaidDevice
f@f-SATA:~$