F5221 - Rebuilt RAID 5 but building again?

[Darren]

Hi,

Recently added a 5th HDD. Expansion/rebuild took several days but eventually I got my push email to say 'congratulations the rebuild is complete'.

When I checked the TOS it appears the rebuild is starting again.

Why would that happen?

[Darren]

Actually it seems thus second phase is 'synchronising' - should this be a relatively quick process compared with the rebuild?

Are there more phases after this?

[TMRyan]

Hi,

This is a normal situation, it will synchronize the original array after the expansion is successful.
The synchronization time depends on the size of your hard disk, and different hard disks will have different synchronization speeds.
There will be no more stages after the synchronization is complete.

E.g:
Seagate 12TB NAS Red Disk
Synchronization completion time: 17 hours
196MB/S

Normal: Samsung 750 EVO SSD 120GB
Synchronization completion time: 14 minutes and 32 seconds
232MB/S