Hello and thank you for such a great project!
I just finished installing Xpenology with DSM 6.1.5 and 5 x 8TB drives. This is a fresh install. I chose to create an SHR-2/BTRFS volume with those 5 HDDs, which should have netted me 24TB of storage, with two drives of parity for fault tolerance. Now, I know this is not really 24TB as each 8TB drive is really 7.28TiB. But still, I should end up with ~21.84TiB of storage space. My system is showing that the volume I created has capacity of 20.95TiB. Where did I lose that one TiB of space? Overhead or SHR-2? If it is because of any of these, are there any alternatives so that I can recoup that lost space? What if I use just plain RAID6 or change to ext4? I still have not put any data on the drives, so can redo/change my previous selections. Any ideas/explanations are welcome.
Thanks!