NAS setup in RAID1 with disks >2TB, possibly with encryption

Turris Omnia
3

It is possible to use a disk without partition:

mdadm --create /dev/md0 --level=mirror --raid-devices=2 /dev/sda /dev/sdb

But then I have following issue:

[681065.017730] ata2: hard resetting link
[681075.022738] ata2: softreset failed (1st FIS failed)
[681075.027731] ata2: hard resetting link

Which is described here: