On Friday, 12 October 2018 13:37:22 UTC+1, George Miles wrote:
rob wrote [
That only works as long as you remember to save a fresh copy of
anything that changes, or regularly save everything then de-dupe it. ]

No, in my windows 10 when i select and copy a folder then paste it into my backup folder on external hard drive windows asks if i want to overwrite or skip duplicated files with the same date.

Yes because that is classed as a copy NOT a backup , the clue here is when you 'copy' the folder.
if I do this on my mac I get an extra option to merge the files, skip or replace.

A backup system would lok at the name of the file thens it;s creation date and the modified date if the modified date is more recent then it will copy just those files over to your backup. Proper backup software would NOT delete the older file but would create a new one, without deleting the old one, just in case you need it.



Skip is a lot faster

Yep it skips files, skip the whole folder and it copies really fast ;-)


[g]