Can I back up to mapped MyBook Duo?

I bought a MyBook Duo for use as a backup unit for my Synology NAS unit. It’s attached to the USB 3.0 port on the NAS. Each of the NAS and the MyBook Duo has two 6tb WD Red drives in RAID1 configuration. This is clearly overkill for a backup unit, but I really do want to safeguard this data.

I have mapped the NAS’s shares and the MyBook to my Windows 10 computer, so that each has a drive letter and can be seen as a drive on my computer. Unfortunately, even though the OS can see the shares and the MyBook as drives, the WD software cannot. I thus can’t run SMART testing on the MyBook using the drive utilities and I cannot run a backup from either the NAS shares or from directories on my computer’s internal drives.

I know that backup software can recognize shares – I’ve been using FreeFileSync for years between mapped drives – but, for some reason the WD software cannot. While I am primarily interested in using the disk utilities, I’d also like to run some backups from the NAS mapped drives to the MyBook Duo just to see if I can speed up a pretty slow backup operation using either FreeFileSync or the OS copy routine.

Is there something I can do to enable the mapped drives to be recognized by the WD software suite?

WD SmartWare does not support USB drives over the network at the time of this post. It does support WD NAS devices, but USB devices need a direct connection.

Thank you for letting me know.