ReadyNAS Device Compatibility List

Hi All,
Starting State
ReadyNAS Ultra 4 with 4x1TB Hitachi HDS721010CLA332, X-RAID2
HCL info on non-listed 3TB drive.

Went looking for a 3TB, found a western digital on the HCL WD30EZRS
found a store that had them, went in and they were actually WD30EZRX

I explained the situation that the disks needed to be a specific model.
The WD30EZRS is supposedly discontinued, replaced by the WD30EZRX model.
The guy said I could try them, and return them if they didn't work, so ...hey, gave 'em a try.

powered off, swapped disk1 out for the first 3TB.... the RAID re-synced showing 927 GB allocated.
powered off, swapped disk2 out for the second 3TB.... the RAID re-synced showing 927 GB allocated.
Then got messages saying that expansion has been identified or something like that and that volume would be expanded upon next reboot.
So...rebooted....volume expanding

so far so good!
Current State
ReadyNAS Ultra 4 with 2x3TB Western Digital WD30EZRX, 2x1TB Hitachi HDS721010CLA332, X-RAID2