Thanks again, dosborne. It is great to have possitive feedback to questions like this to learn from.
I followed the link you provided and found the Ext viewing freeware ext2explore mentioned in the thread. I attached one of the 1TB drives to the computer I was using and same problem, the linux partitions could not be seen by the program??? I took the drive to another computer, re-ran the program and poof, there they were; all visible and accessible!! I must have the other machine set up differently somewhere or it may be the USB HUB I used that caused the problem on the original computer.
Unfortunately, by the time I got this to work, I had already removed the 2TBs from the unit and slapped one of the 1TBs back into the DNS-323 and had began copying files to one of my other boxes. (Oh well, ALWAYS GOOD TO HAVE AN EXTRA BACKUP or 2, JUST IN CASE!!)
As for the mirroring of the image after the auto-rebuild from the 1TB to the 2TB drive, you were correct (as I suspected you would be.) The image on the 2TB I had used in the first rebuild became an exact duplicate of the 1TB drive.
The DNS-323 did give me the option of erasing everything and to re-format the drives to 2TB Raid or to assign the unused room of 1 drive into a JBOD when the 2nd auto-rebuild completed.
The unit could not see the unused portion of the 1st 2TB drive and would not allow me to create a 2nd raided partition. The only selectable option was JBOD.
I tried to create the JBOD partition but after the format the Raid1 partition disappeared and out of the 4TBs in the unit, I only had the 1TB JBOD partition on the drive in the left slot for use (This became native volume 1.) The DNS could not see the Raid partition between the drives I had created in the 2nd rebuild or the other unused portion of the first 2TB drive in the right slot. (Gawd, I love computers.)
So, I now have a 1 and half day task of allowing the DNS to finish feeding files to the computer and another day and a half of pushing them back to the 2TB Raid1 config.
It would be nice to have a function or an utility built into the firmware that would allow for easier upgrading of drives. Can you pull any strings?
Again, thanks for the great input.
Pte Jack