Some file types seem to change in ways such that rsync's algorithm wouldn't be any better that just straight copying the file. For instance, if a gzipped file is uncompressed, changed even by 1 char at the beginning, and recompressed, the result can have very little in common with the original (in terms of identical blocks). But then again the gzipped files might have a lot in common if the change occurs near the end, as it would for a log file that was updated. So, in practice, which file types it is not worth running the rsync algorithm on? Does rsync ever look at file extensions, etc, and from that try to figure out if it running the algorithm would be worth it? Thanks. -- Ben Escoto