New to NAS: Initial setup of a ReadyNAS DUO 2000

xm8 wrote:
What I want from the NAS: 1) The disks to behave as seperate volumes (I have no need for any RAID functionality). 2) Have Disk 2 be the backup of Disk 1.

That's not really different from X-Raid or even Raid1. The true purpose of a real backup is to provide another source/device for your data. If your primary is volume C: in the Duo and your backup is volume D: (the other drive), what happens if something happens to the Duo (fire, theft, storm, accident)?.

In fact, your plan can be more effort than the default X-Raid. If you lose either drive during X-Raid, upon hot adding the replacement drive, the system will resync the two drives automatically. If you have two Raid0 volumes, one a manual backup of the other, and you lose one drive, then after you go through the effort of re-establishing the second volume again, you must then manually perform the backup again.

If you use X-Raid, when you create, save, modify a file, the second drive has the same exact information at the same time (2 drive array is mirrored).

I would continue with the X-Raid installation and copy the data from the USB external drives. I am assuming they are all smaller that the drives you are installing in the Duo (you have not given drive specs). You could then use the USB drives to back up the volume on the Duo, and they would be true backups as the data would then be on a separate device, not just a separate drive.