I added my 4TB drive to the mix over the weekend. I was going to go with SH2 which allows for 2 drive failures, but it really eats up my space. I just ended up sticking with SH1 for 1 drive failure and more space. I am still pretty safe, unless another drive would fail during a rebuild of the 1 drive failure. But it went smooth, popped it in, went to the management panel and added it. It checked for concinnity of the drives which took most of the day on a 4B drive. After that the space was available. I also added more data to my cloud backup, which I have scheduled to run at 2 a.m. daily.