I've only ever used CCC a couple of times and on each occasion it's always been near to the same GB as the SSD/HDD. SSD at 500GB and about 400GB used, and the CCC was around the same when copied, and the same 100GB remaining on the drive. I've never actually added/updated to it, instead of cloning the drive from scratch as previously done. Today I updated/added and the SSD shows 100GB remaining still, but the CCC clone SSD shows 70GB remaining. I was under the impression that if the drive fails and I want to use the CCC it was an exact clone, so why has it got an extra 30GB of data on it? Thanks for any help.