Our 24 disk "1 x fat RAID6" rebuilds something between 14h and 53h depending on your settings for write cache and background task priority.

As a RAID6 it performs quite well, although there are some remaining issues with NFS mounting and web administration - but that is no issue to RAID5, RAID6 (small or fat) - at least I hope.

But probably other colleagues could state their configuration and rebuild times, so we get an overview about different configurations.

Koroljow.