I've set up a test instance with raidF1 to try how one can recover data in case of any failure.
I've attached the three virtual disks inside my debian system (proxmox) under the following device names:
/dev/nbd0
/dev/nbd1
/dev/nbd2
output of lsblk
# lsblk -f
NAME FSTYPE FSVER LABEL UUID FSAVAIL FSUSE% MOUNTPOINT
nbd0
├─nbd0p1 linux_raid_member 0.90.0 53e00d47-f1a3-66c2-05d9-49f7b0bbaec7
├─nbd0p2 linux_raid_member 0.90.0 f7d63632-735b-1692-05d9-49f7b0bbaec7
└─nbd0p3 linux_raid_member 1.2 test:2 c63ed2c8-39a8-7ff0-2c43-0f774cb603c9
nbd1
├─nbd1p1 linux_raid_member 0.90.0 53e00d47-f1a3-66c2-05d9-49f7b0bbaec7
├─nbd1p2 linux_raid_member 0.90.0 f7d63632-735b-1692-05d9-49f7b0bbaec7
└─nbd1p3 linux_raid_member 1.2 test:2 c63ed2c8-39a8-7ff0-2c43-0f774cb603c9
nbd2
├─nbd2p1 linux_raid_member 0.90.0 53e00d47-f1a3-66c2-05d9-49f7b0bbaec7
├─nbd2p2 linux_raid_member 0.90.0 f7d63632-735b-1692-05d9-49f7b0bbaec7
└─nbd2p3 linux_raid_member 1.2 test:2 c63ed2c8-39a8-7ff0-2c43-0f774cb603c9
output of mdadm examine. Here the problems begin as Raid Level is "-unknown_"
# mdadm --misc --query --examine /dev/nbd0p3
/dev/nbd0p3:
Magic : a92b4efc
Version : 1.2
Feature Map : 0x0
Array UUID : c63ed2c8:39a87ff0:2c430f77:4cb603c9
Name : test:2
Creation Time : Mon Sep 19 20:56:50 2022
Raid Level : -unknown-
Raid Devices : 3
Avail Dev Size : 45660160 (21.77 GiB 23.38 GB)
Data Offset : 2048 sectors
Super Offset : 8 sectors
Unused Space : before=1968 sectors, after=0 sectors
State : clean
Device UUID : 426bd125:fbf2912a:c8e7d1ec:2fe2e307
Update Time : Mon Sep 19 21:48:24 2022
Checksum : 27a0eb8a - correct
Events : 23
Device Role : Active device 0
Array State : AAA ('A' == active, '.' == missing, 'R' == replacing)
Then trying to reassemble
# mdadm --assemble --force --uuid=c63ed2c8:39a87ff0:2c430f77:4cb603c9 /dev/md127
mdadm: /dev/md127 assembled from 3 drives - not enough to start the array.
Output of mdadm now states that the raid is a raid0
# mdadm --detail /dev/md127
/dev/md127:
Version : 1.2
Raid Level : raid0
Total Devices : 3
Persistence : Superblock is persistent
State : inactive
Working Devices : 3
Name : test:2
UUID : c63ed2c8:39a87ff0:2c430f77:4cb603c9
Events : 23
Number Major Minor RaidDevice
- 43 3 - /dev/nbd0p3
- 43 51 - /dev/nbd2p3
- 43 19 - /dev/nbd1p3
What do I have to do different to assemble it successfully? I had the assumption it would be assembled as an raid5 but this does not seem to be the case.
