rsync adalah utility u/ memindah2 file/sinkronisasi file.
Kata manualnya sih rsync bisa digunakan sbb :

1. for copying local files. This is invoked when neither source nor destination path contains a : separator
2. for copying from the local machine to a remote machine using a remote shell program as the transport (such as rsh or ssh). This is invoked when the destination path contains a single : separator.
3. for copying from a remote machine to the local machine using a remote shell program. This is invoked when the source contains a : separator.
4. for copying from a remote rsync server to the local machine. This is invoked when the source path contains a :: separator or a rsync:// URL.
5. for copying from the local machine to a remote rsync server. This is invoked when the destination path contains a :: separator.
6. for listing files on a remote machine. This is done the same way as rsync transfers except that you leave off the local destination.

So, yuk mari kita buktikan.

Anggap saja server utama ipnya 10.10.10.75 dan server backupipnya 10.10.10.60
Nah rsync modenya nanti pakai yang over ssh.

Login ke 10.10.10.60, di directory /home ketik :
# ssh-keygen -f qlogin -t rsa
untuk password langsung enter saja, perintah ini akan mengenerate private (qlogin) dan public key (qlogin.pub)

Selanjutnya copykan qlogin.pub ke server 10.10.10.75 di directory homeuser/.ssh dan rename menjadi authorized_keys2, spt ini nih hasilnya : /home/rahma/.ssh/authorized_keys2

Kita tes, sukses ga login ssh scr otomatis..
Login ke 10.10.10.60, masuk ke directory dimana qlogin berada dan ketik
# ssh -i qlogin rahma@10.10.10.75

OK, setelah sshnya lantjar djaja, tinggal install rsyncnya.. (spt biasa wes.. ndak usah dijelasin yak :P)...

Nah untuk perintah sinkronisasi/backup filenya spt ini :
masuk ke dir dimana qlogin (private keynya berada), kebetulan punyaku di /home
# cd /home
# /usr/local/rsync/bin/rsync -e "ssh -i qlogin -l rahma -p 2223" -avz rahma@10.10.10.75:/home/www /home/BACKUP75/

sent 1636 bytes received 2421838595 bytes 3734526.19 bytes/sectotal size is 2421962606 speedup is 1.00