Ups - Sorry:
This is a question for Synology - but other users may then like to read with.
We must work to have bought some storage for archived data. And we have many.
We are thinking of buying the above and fill it up with 3 TB disks, possibly with a shelf more immediately. Can you make one large disk group of up to 22 discs or they shall be made as two disk groups? Is it possible to create Raid 6 plus a hotspare? - Immediately it is not possible on your website but it may be possible anyway?