It is a kind of backup feature. When user starts to do Rsync, the backup data will transfer from client site(source) to server site(target). And Qsan Rsync feature is different with Qreplica, Rsync can backup file by the selected path, and Qrelica only can bakcup all volume/Filesystem. Moreover, if the server or other brand NAS has the Rsync feature, our NAS can do Rsync with them, too. And Qsan Rsync is designed to divide into two mode - server mode and client mode. It would be more compatible.