DOM is maybe. I do not understand how to test externally. I tested fsck and no errors. So not convinced into that.
I found this for other model that somehow resembles my situation: What sequence should I follow when updating firmware on TS-231+/TS-431+? | QNAP
The TS-X31+ series NAS needs to be updated in the following sequence:
QTS 4.2.0_20160311 > QTS 4.2.6_20170531 > QTS 4.3.6_20190919 > latest QTS version.
I experienced that I can update to 4.2.2 (found on internet) but missing 4.2.6 to go to 4.3.6 (from qnap.ru). QNAP is vey unhelpful to explain or provide. They suggest to trade in this one for a new model!?
They scrubbed old firmware and also BIOS for my and many other models.I see instructions to update BIOS (my should be Legacy), but not BIOS itself.
When I update to 4.2.2 I get blue screen of initialization, how to avoid that.
When I look disks I insert, they are all there, but RAID does not seem to be present. Previously data was in /share.
Is RAID data distroyed, or it’s access changed in the meantime?