I have a ReadyNAS NVX Pioneer Edition which currently has 3 x 1TB drives in a single X-RAID2 configuration. I'm about 75% full so am starting to shop for new drives. Is buying a single 3TB drive for the 4th bay going to net me any increase, or will I need to get at least 2 drives before the additional space becomes useable in X-RAID2?
I was in a similar situation except I had 4x1TB ST31000528AS drives. I had a redundant volume of about 2.8TB (you should have about 1.9TB). I then acquired 2xHitachi HDS5C3030ALA630 for vertical expansion. When I installed the first, I did not expect, nor did I receive any volume increase. After installing the second, no increase was received initially. After the resync of the volumes, you should get the same message I did that expansion will continue after a restart.
I actually went through this twice since I have an NVX Pioneer (backup) and an NVX Business Edition (primary). As I recall, the Pioneer expanded after one reboot, and the BE took two. Afterwards, I now have a redundant volume of 4.5TB. This is the result of the second layer of 2TB gross, 1.8TB net.
The expansion went as planned. I would recommend that you make sure you have a current and complete backup before proceeding. It is never a bad idea to maintain one. I chose to upgrade my backup system first to make sure the expansion did not throw any curves at me. But, one never knows, and it is always comfortable to have a good backup and not need it, than to need it and not have it.
