I see why RAID rebuilds obstruct data migration. A RAID rebuild is NOT like backup and restore.
The rebuild consumes resources, e.g. CPU etc. So if we have the RAID on a separate system (managed by its own CPU) then: Surely this allows a RAID rebuild without obstructing data migration? Do you envisage other options to rebuild RAID without mega-impact on data migration? Or do we take the pain (i.e. wait until the RAID rebuild completed BEFORE starting the data migration?)