How to Upgrade Disks in ReadyNAS Duo V1

One thing to check is whether you have 4K alignment. That doesn't matter for your existing drives, but it is needed for best performance with the 2 TB ones. In order to figure this out, read through the guide here: http://www.rnasguide.com/2011/06/22/why ... -readynas/ The relevant section is "4k sector partition alignment" about half way down the web page.

If you don't have 4K alignment then it is best to do a reset, and not expand. If you do have 4K alignment, then expanding will be fine.

You have the right idea overall on how to handle the reset, here's a slightly expanded view of the steps.
(a) back up your data
(b) update your firmware (esp. if you are running 4.1.7 or earlier).
(c) back up your config (using frontview as you say)
(d) Note whatever add-ons you have installed (via Frontview).
(e) Power down, remove your two disks, and label them. (You could still reinsert them if you needed to later on).

Then on the rebuild steps
(1) insert the two new disks (unformatted)
(2) Power up the NAS - it will do a factory install. Admin password will be netgear1.
(3) Reinstall any add-ons (BEFORE restoring the config)
(4) restore the config zip using the method you said.
(5) Restore the data.

If you don't need a reset, then the full process is
(a) back up your data
(b) update your firmware (if desired).
(c) back up your config (using frontview as you say)
(d) remove disk 1 with the NAS running, and then hot-insert a new disk into the NAS.
(e) wait for the resync to complete. Volume size will still be 500 GB.
(f) remove disk 2 with the NAS running, and hot insert the second new disk into the NAS
(g) wait for the resync to complete. Volume size should expand to 2 TB (a reboot might be needed after the resync for this to happen).

It's not as hard as all the steps make it sound...

For restoring the data, all you really need to do is create a new "restore" backup for each of your two shares - reversing the source and destinations in your current backup jobs.

Though it is much faster to copy the data using a PC over an ethernet connection (assuming they are formatted USB or NTFS). You can connect them to the PC and use teracopy to copy them back. I suggest teracopy because it can verify the data.

If you aren't confident that your USB backups are complete (or that the drives are solid), you can also make a full backup using teracopy and a PC. That should take about 6-8 hours. Probably worth the time.