I have 3 drives. For this purpose, we will call them A, B and C respectively.
A is 2 TB
B is 1 TB
C is 500 GB
I have already run
rsync -avz -progress A B
Now B is full and I want to move/copy what is not already on B from A to C
It really doesnt matter to me what happens to what is on A as I will reformat anyways.