1. Yes, if you can find one with the right dimensions and connectors ... there is nothing technically that would prevent "blu-ray" specifically from working in it. 2. There is no 4TB limit. 4TB may just be the largest model they tested and validated for it. The H710 is not a validated controller for the x710 servers though - you should be using the H700 in that server. Either way, there is not a 4TB limit. It may not be able to handle 4kn/AF drives - and don't use NAS drives - but other than that, nothing technical that would limit the size to 4TB.
  I recently picked up a 710 and have decided to try to breath some life into this workhorse. 1. Is it possible to remove the DVD drive and install a blu-ray in its place?  2. I've read that the H710 raid controller can handle hard drives up to 4tb. Is it possible to have larger drives, with this, or a different controller?
R710 upgrades