"Bill Holland" hollandwl@gmail.com writes
I suspect that Option 4 (Initialize all disks) only wipes out the metadata and does not actually rewrite any disk blocks as it does not take very long to complete
It's only fast if the disks are pre-zeroed, surely?
disk zero spares zero's out all your spare disks. The benefit of this is faster rebuild of a spare should a disk fail. If the spares aren't zero'd the first thing ONTAP will do when it grabs a spare is zero it, thus taking longer to rebuild
No. Having a spare pre-zeroed makes it fast to add it to an aggregate (or traditional volume): it is in that case that it otherwise has to be zeroed first (to maintain correct parity). It makes no difference whether it is pre-zeroed or not if it is used in a RAID rebuild after a disk failure.