Unrecovered read error during raid1 rebuild after disk upgrade

Hi,I wanted to replace the drives in my RAID 1 array with larger ones in my TS-253 Pro, using the “replace disks one by one” method. I started by removing the disk from slot 1, waited for the beeps, and then inserted the larger replacement drive. The RAID rebuild started automatically using the disk in slot 2, but it failed after a few percent with a read I/O error (“unrecovered read error”). Since then, the RAID has been degraded. QTS said i should run a bad block scan, but I’m afraid to start it as it might harm the disk even more.

Based on recommendations I found on forums, I started backing up the data over SMB using FreeFileSync. During the backup, I received another message:

RAID group “1” is degraded. Volume: DataVol1. The group has been set to read-only. Back up all data immediately.

At the same time, FreeFileSync reported that it could not access the lock file it created:

Cannot write file “\…\sync.ffs_lock” ERROR_WRITE_PROTECT: The media is write protected. [CreateFile]

Because of this, I guess the disk currently in slot 2 may no longer match the disk that was originally in slot 1 (the one I removed).

Once I have completed the backup, how should I proceed?

Should I replace the degraded slot 2 disk with the original disk from slot 1? If I do that, will the RAID rebuild automatically from that disk? The replace disks one by one option is currently disabled. What if that disk also has issues?

Thank you in advance for any tips.

• This topic was modified 1 month ago by bimodo.