Thank you for the reply, Bighorn.
Not sure I follow your thoughts regarding the mirror drive. Idea is to save files if Disk 0 fails physically. Your statement, "...backing up to or mirroring to that partition could cause loss of all data if the drive fails..." is referring to a software issue, so that both Disk 0 and Disk 1 end up as corrupt? Do I have that right?
I am using Disk Management for the mirror. Both drives are equal capacity SSDs and I am following guidelines:
1) Open Disk Management - new drive is recognized by WIN 10 Pro
2) Right-click drive to be mirrored, Disk 0 C:
3) From menu choose Add Mirror...
4) Window opens to select location for mirror, Disk 1
5) Click Add Mirror
6) Warning appears saying converting disks to dynamic prevents starting system from any but boot volume
(which is Disk 0, C
7) Click Yes, and error shows, "There is not enough space available on the disks to complete this operation."
I tried creating a volume in Disk 1 first, but attempt to mirror Disk 0 (C
shows grayed out option for Add Mirror...
So, I'm thinking a 3rd party mirroring utility may be needed. any more thoughts?