On Jul 10, 2015, at 8:38 PM, Andrey Repin <anrdae...@yandex.ru> wrote: > >> Consider all the disk I/O required. In its default mode, rsync must do a >> full directory tree scan on the directory to be transferred, on *both* ends. >> For each file with a different mtime or size, it must then recompute all the >> hashes in that file, again on both sides. > > Wrong. In default mode, rsync only care about timestamp and size. > It will not go on hashing crusade unless explicitly told to.
You misunderstood what I wrote. Given a changed mtime or file size, rsync then must re-read the file on both sides in order to generate a series of checksums on chunks of the file in order to determine which parts of the file have changed, so that it transfers only the changes. See: https://en.wikipedia.org/wiki/Rsync#Determining_which_parts_of_a_file_have_changed If you skip this step, you must transfer the entire file contents to the other side, since a difference only in the mtime and/or file size doesn’t tell you which parts of the file have changed. -- Problem reports: http://cygwin.com/problems.html FAQ: http://cygwin.com/faq/ Documentation: http://cygwin.com/docs.html Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple
