40 days for rebuilding a 4TB failded hard drive?

After replacing a hard drive in MyCloudEX2Ultra, 4TB Raid 1 mode, it took about a day for Auto-Rebuild. After that the system reports that both disks are Ok and the Raid is healthy. Nevertheless, when login on the drive (Storage->RAID), it shows:

3.93 TB Rebuilding (Drive1), 3%, 59152 min

There is no sign that the SAN is not working properly, just that I would like to understand better how it works. Is it normal rebuilding of a 4 TB hard drive to take 40 days?

I’ll appreciate any comments or links which can shed some light on the subject.


Right now I have the same problem more or less. The device has been locked during the day constantly, and I had to turn it off and on again. Now it shows, but It is increasing gradually:

Volume_1 RAID 1 2.94 TB Rebuilding, 11.1%, 338 mins

I have a MyCloudEX2, 3TB Raid 1 mode.


Which firmware are you using?