Have been using CCC for some time for local files and is very good at what it does however it does not recommend backing up networked files for unreliability reasons. All my files are on my iMac which have been copied and pasted to the internal ssd on my Nucleus. So looking at it logically already have a backup but still backup my iMac files on two external drives. One ssd and one spinner. When not if the ssd in the Nucleus dies will have to copy and paste all files again but to be honest it does not take long to copy large Hi-Res files this way.