-O, --omit-dir-times omit directories when preserving times
-S, --sparse handle sparse files efficiently
-n, --dry-run show what would have been transferred
- -W, --whole-file copy files whole
+ -W, --whole-file copy files whole (without rsync algorithm)
--no-whole-file always use incremental rsync algorithm
-x, --one-file-system don't cross filesystem boundaries
-B, --block-size=SIZE force a fixed checksum block-size