Rebuilding time

Several days ago I replaced the RAID drive which I assumed was drive 2. To provide off site storage of back up. All worked well. New drive installed, but therebuilding process moves very very slowly. It looks like it will take almost 80 days to complete the rebuilding process. That seems crazy. am I doing something wrong?

Sometimes due to initial drive system check process, RAID rebuild process takes longer time than usual. However, it is recommended to don’t interrupt the RAID rebuild process as it may affect the performance of drive and data. You may refer below link more assistance related to RAID Rebuild process: