rsync and backup files

rsync -r -t -v --progress -o -g -p -x -u -l  /fromdir/ /backupdir/

-r copies also all subdirectories within main directory

-t preserves modification times

-v verbose mode, shows more information

--progress shows progress during transfer

--delete deletes files in destination which are not present in the source

-c compares files contents by checksum

-l copies symbolic links

-z compresses files for faster transfer

-x don’t cross filesystem boundaries

-o preserves owner

-g preserves group

-p preserves permissions

-u update