Nextcloud - PI4 - 2nd hdd issue

I have NC running on a new PI4 B with a single 4T hdd drive(formatted with NC).
This configuration works fine and “lsblk” is showing up sda1 with the correct mountpoint to myCloudDrive.

If I put a 2nd hdd drive(win format) into the PI4 the “lsblk” is showing no sda storages.
Any ideas how to use 2 hdd drives ?

Reason 1:
I would like to copy large data from sda2 to sda1 by using “rsync” cause the webtransfer of large data is to slow or do i miss a thing ???

Reason 2:
I would like to use raid options at a late state