Unity 300F dynamic pool expansion questions

Hi there, we have a Unity 300F, it is currently configured as RAID5(8+1) and (+1) hotspare

There is a "traditional" storage pool on it already, and data in it, and we need to expand it

So, we have upgraded to 4.2, and want to use dynamic pools

It looks like we have to destroy the current traditional pool (and move the data elsewhere temporarily), create a new dynamic pool with the 10 drives in the pool, then move the data back into objects in the pool

So, from my understanding, we can get our new drives over time and incrementally expand this dynamic pool by adding +1 drive at a time, and it will re-balance across the new grand total# of disks

• Does anybody have a real world time metric to complete the re-balance from 10x7TB drives to 11x7TB drives?

Then, when I reach 14 drives, the system would re-balance again going from RAID5(8+1) to RAID5(12+1) across all disks in the pool

• does it need "extra free overhead space" to do this?
  • i.e. can I go from 13->14 disks (at 95% pool consumption) and still re-balance when I get the +1 drive?
  • or would I have to go +2 drives at the next RAID step?

Also, this looks like a complete task that is done by end-user/administrator, so just to verify:

• Does this require any EMC tech support to perform any tasks?

Thanks.