JavaLawyer,
For the past couple of years I used a pair of 1.5 TB Seagate ST 31500541AS hard drives configured as RAID 1. They both gave reliable service. I don’t see them listed.
Last week I switched them out for a pair of 2.0 TB Seagate ST2000DM001 hard drives configured as RAID 1. I don’t see them listed either. They formatted to full capacity and passed both the SMART and scan disk tests. 1.1 TB of data copied back to them @ 19.1 MB/sec. over GBit Ethernet.
On 23 Oct 2014 I installed a brand new pair of Seagate ST3000VN000 hard drives configured for RAID 1. Contrary to the above post, they only formatted to ~768 GB, similar to formatting them under Windows XP. Right or wrong, I concluded that the DNS-320 only supported drives up to a 2.2 TB limit.
Hope this information helps other users.