There is a directory A whose contents are changed frequently by other people.
I have made a personal directory B where I keep all the files that have ever been in A.
Currently I just occasionally run rsync to get the files to be backed up from A to B. However I fear the possibility that some files will get added in A, and then removed from A before I get the chance to copy them over to B.
What is the best way to prevent this from occurring? Ideally i'd like to have my current backup script run every time the contents of A get changed.