Is it safe to shutdown a machine while rebuilding/recovering/growing a RAID5 array that was built with mdadm

I have recently started a recovery on my 5-drive RAID in my file-server, and it says it'll take 691+ minutes to complete. I was wondering what would happen to the process if the machine lost power - say in a blackout? Would I need to restart the recovery process again? Would I lose the whole RAID of data?

Also, what would happen if I was in the process of growing the RAID and the power went out?

From serverfault phalacee

• A normal shutdown is well managed by mdadm, but a blackout (as always) may be tragic.

  phalacee : If I shut it down (or more likely, my wife decides to shut it down) would it mean I need to restart the recovery/growth of the array, or would the next boot of the machine resume it from where it left off?

  Jasper : The recovery/growth will start all over again.
  From lg