New disk does not become a "system disk" after replacement via TOS
Posted: 07 Jul 2025, 19:46
Hello!
I’m using a TerraMaster F4-212 with 4×1TB HDDs in TRAID, running TOS 6. Recently, I began upgrading the drives one by one to larger capacity disks.
I replaced one 1TB drive with a 6TB drive using the standard procedure via the TOS interface. Everything appeared fine at first — the partitions were created automatically (root, swap, data), and the RAID5 volume (md0) started rebuilding as expected.
However, I noticed something strange:
Although the new disk had the same partition layout as the others, it was not added to the system RAID arrays:
The root partition wasn’t added to /dev/md9
The swap partition wasn’t added to /dev/md8
As a result, the disk was not marked as a “system disk” in the GUI.
I do know how to manually re-add the partitions using mdadm --add and mdadm --grow, and that worked fine. But this behavior seems risky.
What worries me:
If a user replaces all four disks one by one — and TOS doesn’t automatically include the new drives in the system RAID arrays — they could end up with no remaining system disk, which might make the system unbootable, even though the data RAID is perfectly healthy.
I believe this behavior should either be improved or accompanied by a clear warning during the disk replacement process.
Thank you for your efforts and for bringing TOS 6 to ARM devices — it’s greatly appreciated.
Kind regards.
I’m using a TerraMaster F4-212 with 4×1TB HDDs in TRAID, running TOS 6. Recently, I began upgrading the drives one by one to larger capacity disks.
I replaced one 1TB drive with a 6TB drive using the standard procedure via the TOS interface. Everything appeared fine at first — the partitions were created automatically (root, swap, data), and the RAID5 volume (md0) started rebuilding as expected.
However, I noticed something strange:
Although the new disk had the same partition layout as the others, it was not added to the system RAID arrays:
The root partition wasn’t added to /dev/md9
The swap partition wasn’t added to /dev/md8
As a result, the disk was not marked as a “system disk” in the GUI.
I do know how to manually re-add the partitions using mdadm --add and mdadm --grow, and that worked fine. But this behavior seems risky.
What worries me:
If a user replaces all four disks one by one — and TOS doesn’t automatically include the new drives in the system RAID arrays — they could end up with no remaining system disk, which might make the system unbootable, even though the data RAID is perfectly healthy.
I believe this behavior should either be improved or accompanied by a clear warning during the disk replacement process.
Thank you for your efforts and for bringing TOS 6 to ARM devices — it’s greatly appreciated.
Kind regards.