I have a Western Digital 250Gb Passport drive for backing up my Windows laptop. I figured I would just use cygwin rsync to move data between the two drives. When I mount the Passport as drive Q, I use a command like this:
rsync -az --progress . /cygdrive/q/bak
This faithfully copies all the data, and avoids copying stuff that hasn't changed, mostly. But some files are copied every time I run the command, even when they haven't been changed, and in fact, a diff program shows that the source and the backup copy are identical. I figure it's some Windows characteristic of the file that is throwing off rsync and making it think the file needs to be copied, but I can't figure out what. Some of the files have capital letters in the filename, but not all of the afflicted files do. I never set permissions on files, so I don't think that could be it (but I could be wrong).
Anyone have any experience with this?