rsync -avuz
-n show what would have been transferred
-a archive mode; same as -rlptgoD (no -H)
-H preserve hard links
-r recurse into directories
-l copy symlinks as symlinks
-p preserve permissions
-t preserve times
-g preserve group
-o preserve owner (super-user only)
-D same as --devices --specials
--devices preserve device files (super-user only)
--specials preserve special files
-v increase verbosity
-u skip files that are newer on the receiver
-z compress file data during the transfer
-c skip based on checksum, not mod-time & size
--delete delete extraneous files from destination dirs
-P same as --partial --progress
