RAID0 recovery

[Pegasus]

Hey! In xpenology I have 2 disks (4TB and 500GB) and RAID0 (4TB + 500GB). Decided to update from DSM 6.1.7-15284 with jun's loader to 7.1 with ARPL. Successfully updated and founded that RAID0 become unavailable, but it was still existed in storage manager. Seeing this with horror, I decided to roll back (my bad) to 6.1.7-15284. I changed USB stick, booted up with 6.1.7-15284, xpenology suggested a migration or reinstall (screenshot). Migration was unsuccessful because I had to download a version higher than the current one, 7.1. I selected reinstall option (there was a text that the data will remain unchanged after reinstall).

 

Then when I boot with 4TB (port 1) and 500GB (port 5)  connected drive I haven't see a broken RAID 0.

 

$ cat /proc/mdstat
Personalities : [linear] [raid0] [raid1] [raid10] [raid6] [raid5] [raid4] [raidF1]
md1 : active raid1 sde2[1] sda2[0]
      2097088 blocks [12/2] [UU__________]

md0 : active raid1 sda1[1]
      2490176 blocks [12/1] [_U__________]

unused devices: <none>

 

 

When I boot only with 4TB connected drive I see:

$ cat /proc/mdstat
Personalities : [linear] [raid0] [raid1] [raid10] [raid6] [raid5] [raid4] [raidF1]
md2 : active raid0 sda3[0]
      3902196544 blocks super 1.2 64k chunks [2/1] [U_]

md1 : active raid1 sda2[0]
      2097088 blocks [12/1] [U___________]

md0 : active raid1 sda1[1]
      2490176 blocks [12/1] [_U__________]

unused devices: <none>

 

$ sudo mdadm -D /dev/md2

/dev/md2:
Version : 1.2
Creation Time : Fri Jan  1 00:51:57 2021
Raid Level : raid0
Array Size : 3902196544 (3721.42 GiB 3995.85 GB)
Raid Devices : 2
Total Devices : 1
Persistence : Superblock is persistent

Update Time : Mon Nov 28 02:38:27 2022
State : clean, FAILED
Active Devices : 1
Working Devices : 1
Failed Devices : 0
Spare Devices : 0

Chunk Size : 64K

Name : NL_SERVER:2  (local to host NL_SERVER)
UUID : 077dbff9:732a2154:186bcfa5:6bde5b9e
Events : 10

Number   Major   Minor   RaidDevice State
0       8        3        0      active sync   /dev/sda3
-       0        0        1      removed

 

S.M.A.R.T of both disks are perfect. It's fully software trouble. I think that when I rolled back in panic to DSM 6.1.7, I erased RAID0 metadata on a 500GB disk? Is the metadata that stores information about raid0 the same on both disks or is it different? Perhaps it can be transferred from a 4TB HDD?

 

I will be very grateful for any help.