I have a TS-639 Pro Turbo NAS Server with six WD 2TB disks configured in RAID6. Yesterday I found out that two disks had problems (disk 3 and 4): disk read/write error. I changed both, but only one is recognised (disk 4). The disk in bay 3 is inserted and the green lamp is burning, so there seems to be any contact, but the green lamp is burning steady (so no disk action) and when I view the settings, QNAP tells me "no disk" in bay 3.
I had another spare disk and I put that one in bay 3 but no difference. When I connect these two spare disks directly with my computer, both seems to be OK.
At this moment, the system is rebuilding the RAID6 configuration with the 5 disks. Could that be the reason the system doesn't see the disk in bay 3, is the RAID6 rebuilding the new disks one after another? Or is something else wrong?