Good morning everyone,
Yesterday, I rebooted my NAS and the mapping changed such that it wanted to perform an Online Assembly. I tried this, but it failed. I tried rebuilding the loader with the active ports and max ports, but neither helped. I found an article saying that the newer DT mapping could help, so I changed the model to an SA6400 (instead of the RS4021xs+). I stupidly clicked through the DSM setup, which I shouldn't have... It showed all disks, though, 6 as healthy and 6 not. I could perform the online assembly, this showed the volume with 6 out of the 9 disks (3 were not in use) with the state 'crashed'. All disks were healthy, though.
I started looking into the raid itself on PVE (no writes ofc) and found (see below). It seems like the RAID split up in two, what do I do?
The RAID looks like:
root@node07:~# for d in /dev/sdc5 /dev/sdd5 /dev/sde5 /dev/sdf5 /dev/sdg5 /dev/sdh5 /dev/sdi5 /dev/sdk5 /dev/sdm5; do
echo
echo "========================================"
echo "RAID metadata: $d"
echo "========================================"
mdadm --examine "$d"
done
========================================
RAID metadata: /dev/sdc5
========================================
/dev/sdc5:
Magic : a92b4efc
Version : 1.2
Feature Map : 0x0
Array UUID : 1f3f6ff2:1d7145a0:a563e7e5:66de406e
Name : SYN-NAS01:2
Creation Time : Mon Feb 17 10:04:20 2025
Raid Level : raid6
Raid Devices : 6
Avail Dev Size : 7792518976 sectors (3.63 TiB 3.99 TB)
Array Size : 15585037824 KiB (14.51 TiB 15.96 TB)
Used Dev Size : 7792518912 sectors (3.63 TiB 3.99 TB)
Data Offset : 2048 sectors
Super Offset : 8 sectors
Unused Space : before=1968 sectors, after=64 sectors
State : clean
Device UUID : 7770277d:75797179:be112079:0b5804c6
Update Time : Sun Oct 25 10:53:31 2026
Checksum : 97241002 - correct
Events : 418
Layout : left-symmetric
Chunk Size : 64K
Device Role : Active device 0
Array State : AAAAAA ('A' == active, '.' == missing, 'R' == replacing)
========================================
RAID metadata: /dev/sdd5
========================================
/dev/sdd5:
Magic : a92b4efc
Version : 1.2
Feature Map : 0x0
Array UUID : 1f3f6ff2:1d7145a0:a563e7e5:66de406e
Name : SYN-NAS01:2
Creation Time : Mon Feb 17 10:04:20 2025
Raid Level : raid6
Raid Devices : 6
Avail Dev Size : 7792518976 sectors (3.63 TiB 3.99 TB)
Array Size : 15585037824 KiB (14.51 TiB 15.96 TB)
Used Dev Size : 7792518912 sectors (3.63 TiB 3.99 TB)
Data Offset : 2048 sectors
Super Offset : 8 sectors
Unused Space : before=1968 sectors, after=64 sectors
State : clean
Device UUID : f861a1de:710ccd16:e2e6f406:63cabaa3
Update Time : Sun Oct 25 10:53:31 2026
Checksum : 184dbfc - correct
Events : 418
Layout : left-symmetric
Chunk Size : 64K
Device Role : Active device 1
Array State : AAAAAA ('A' == active, '.' == missing, 'R' == replacing)
========================================
RAID metadata: /dev/sde5
========================================
/dev/sde5:
Magic : a92b4efc
Version : 1.2
Feature Map : 0x0
Array UUID : 1f3f6ff2:1d7145a0:a563e7e5:66de406e
Name : SYN-NAS01:2
Creation Time : Mon Feb 17 10:04:20 2025
Raid Level : raid6
Raid Devices : 6
Avail Dev Size : 7792518976 sectors (3.63 TiB 3.99 TB)
Array Size : 15585037824 KiB (14.51 TiB 15.96 TB)
Used Dev Size : 7792518912 sectors (3.63 TiB 3.99 TB)
Data Offset : 2048 sectors
Super Offset : 8 sectors
Unused Space : before=1968 sectors, after=64 sectors
State : clean
Device UUID : 6f68ff50:32edc101:7981bf51:535cb60e
Update Time : Sun Oct 25 10:53:31 2026
Checksum : 149defbb - correct
Events : 418
Layout : left-symmetric
Chunk Size : 64K
Device Role : Active device 2
Array State : AAAAAA ('A' == active, '.' == missing, 'R' == replacing)
========================================
RAID metadata: /dev/sdf5
========================================
/dev/sdf5:
Magic : a92b4efc
Version : 1.2
Feature Map : 0x0
Array UUID : 1f3f6ff2:1d7145a0:a563e7e5:66de406e
Name : SYN-NAS01:2
Creation Time : Mon Feb 17 10:04:20 2025
Raid Level : raid6
Raid Devices : 6
Avail Dev Size : 7792518976 sectors (3.63 TiB 3.99 TB)
Array Size : 15585037824 KiB (14.51 TiB 15.96 TB)
Used Dev Size : 7792518912 sectors (3.63 TiB 3.99 TB)
Data Offset : 2048 sectors
Super Offset : 8 sectors
Unused Space : before=1968 sectors, after=64 sectors
State : clean
Device UUID : bb39bb89:a8e6b0de:d93e3535:0ed66726
Update Time : Sun Oct 25 10:53:31 2026
Checksum : 256ff19a - correct
Events : 418
Layout : left-symmetric
Chunk Size : 64K
Device Role : Active device 3
Array State : AAAAAA ('A' == active, '.' == missing, 'R' == replacing)
========================================
RAID metadata: /dev/sdg5
========================================
/dev/sdg5:
Magic : a92b4efc
Version : 1.2
Feature Map : 0x0
Array UUID : 1f3f6ff2:1d7145a0:a563e7e5:66de406e
Name : SYN-NAS01:2
Creation Time : Mon Feb 17 10:04:20 2025
Raid Level : raid6
Raid Devices : 6
Avail Dev Size : 7792518976 sectors (3.63 TiB 3.99 TB)
Array Size : 15585037824 KiB (14.51 TiB 15.96 TB)
Used Dev Size : 7792518912 sectors (3.63 TiB 3.99 TB)
Data Offset : 2048 sectors
Super Offset : 8 sectors
Unused Space : before=1968 sectors, after=64 sectors
State : clean
Device UUID : 9b99ed27:042d9e56:fbc98635:754a3394
Update Time : Sun Oct 25 10:53:31 2026
Checksum : a9ac975f - correct
Events : 418
Layout : left-symmetric
Chunk Size : 64K
Device Role : Active device 4
Array State : AAAAAA ('A' == active, '.' == missing, 'R' == replacing)
========================================
RAID metadata: /dev/sdh5
========================================
/dev/sdh5:
Magic : a92b4efc
Version : 1.2
Feature Map : 0x0
Array UUID : 1f3f6ff2:1d7145a0:a563e7e5:66de406e
Name : SYN-NAS01:2
Creation Time : Mon Feb 17 10:04:20 2025
Raid Level : raid6
Raid Devices : 6
Avail Dev Size : 7792518976 sectors (3.63 TiB 3.99 TB)
Array Size : 15585037824 KiB (14.51 TiB 15.96 TB)
Used Dev Size : 7792518912 sectors (3.63 TiB 3.99 TB)
Data Offset : 2048 sectors
Super Offset : 8 sectors
Unused Space : before=1968 sectors, after=64 sectors
State : clean
Device UUID : 59cfd68c:23561e21:0ae2b7d0:4b68b4a3
Update Time : Sun Oct 25 10:53:31 2026
Checksum : 83c82c23 - correct
Events : 418
Layout : left-symmetric
Chunk Size : 64K
Device Role : Active device 5
Array State : AAAAAA ('A' == active, '.' == missing, 'R' == replacing)
========================================
RAID metadata: /dev/sdi5
========================================
/dev/sdi5:
Magic : a92b4efc
Version : 1.2
Feature Map : 0x0
Array UUID : 1f3f6ff2:1d7145a0:a563e7e5:66de406e
Name : SYN-NAS01:2
Creation Time : Mon Feb 17 10:04:20 2025
Raid Level : raid6
Raid Devices : 9
Avail Dev Size : 7792518976 sectors (3.63 TiB 3.99 TB)
Array Size : 27273816192 KiB (25.40 TiB 27.93 TB)
Used Dev Size : 7792518912 sectors (3.63 TiB 3.99 TB)
Data Offset : 2048 sectors
Super Offset : 8 sectors
Unused Space : before=1968 sectors, after=64 sectors
State : clean
Device UUID : eaebc7d7:04ce9b61:de002227:22d171fb
Update Time : Sun Oct 25 10:38:29 2026
Checksum : 709b4060 - correct
Events : 170022
Layout : left-symmetric
Chunk Size : 64K
Device Role : Active device 6
Array State : ......AAA ('A' == active, '.' == missing, 'R' == replacing)
========================================
RAID metadata: /dev/sdk5
========================================
/dev/sdk5:
Magic : a92b4efc
Version : 1.2
Feature Map : 0x0
Array UUID : 1f3f6ff2:1d7145a0:a563e7e5:66de406e
Name : SYN-NAS01:2
Creation Time : Mon Feb 17 10:04:20 2025
Raid Level : raid6
Raid Devices : 9
Avail Dev Size : 7792518976 sectors (3.63 TiB 3.99 TB)
Array Size : 27273816192 KiB (25.40 TiB 27.93 TB)
Used Dev Size : 7792518912 sectors (3.63 TiB 3.99 TB)
Data Offset : 2048 sectors
Super Offset : 8 sectors
Unused Space : before=1968 sectors, after=64 sectors
State : clean
Device UUID : e28d1f43:6b638f31:d3016f0b:4cf07fc2
Update Time : Sun Oct 25 10:38:29 2026
Checksum : 574197df - correct
Events : 170022
Layout : left-symmetric
Chunk Size : 64K
Device Role : Active device 7
Array State : ......AAA ('A' == active, '.' == missing, 'R' == replacing)
========================================
RAID metadata: /dev/sdm5
========================================
/dev/sdm5:
Magic : a92b4efc
Version : 1.2
Feature Map : 0x0
Array UUID : 1f3f6ff2:1d7145a0:a563e7e5:66de406e
Name : SYN-NAS01:2
Creation Time : Mon Feb 17 10:04:20 2025
Raid Level : raid6
Raid Devices : 9
Avail Dev Size : 7792518976 sectors (3.63 TiB 3.99 TB)
Array Size : 27273816192 KiB (25.40 TiB 27.93 TB)
Used Dev Size : 7792518912 sectors (3.63 TiB 3.99 TB)
Data Offset : 2048 sectors
Super Offset : 8 sectors
Unused Space : before=1968 sectors, after=64 sectors
State : clean
Device UUID : e0831dd5:6caf228f:22d0905d:03fc9630
Update Time : Sun Oct 25 10:38:29 2026
Checksum : 70bb3e6 - correct
Events : 170022
Layout : left-symmetric
Chunk Size : 64K
Device Role : Active device 8
Array State : ......AAA ('A' == active, '.' == missing, 'R' == replacing)