Rsync to updated backup between folder A and B on CentOS Linux

 1. If source is folder A, and destination is folder B, rsync will not produce new folder A in folder B, only backup files under folder A.

> rsync -rulptgo /A/ /B

-r  recursive : recurse into directories

-u  update : skip files that are newer on the receiver

-l  links : copy simlinks as symlinks

-p perms : preserve permission

-t times : preserve modification times

-g group: preserve group

-o owner: preserve owner

-v verbose : increase verbosity

-a  stands for  -rlptgoD