linux backup and rsync

rsync.sh

“As a practical example, let’s consider the imaginary external hard drive that we used earlier with tar. 
If we attach the drive to our system and, once again, it is mounted at /media/BigDisk, we can perform a useful system backup 
by first creating a directory named /backup on the external drive and then using rsync to copy the most important stuff 
from our system to the external drive:
[me@linuxbox ˜]$ mkdir /media/BigDisk/backup
[me@linuxbox ˜]$ sudo rsync -av --delete /etc /home /usr/local /media/BigDisk/backup
In this example, we copy the /etc, /home, and /usr/local directories from our system to our imaginary storage device. 
We included the --delete option to remove files that may have existed on the backup device that no longer existed on the 
source device (this is irrelevant the first time we make a backup but will be useful on subsequent copies). Repeating the 
procedure of attaching the external drive and running this rsync command would be a useful (though not ideal) way of keeping
a small system backed up. Of course, an alias would be helpful here, too. We could create an alias and add it to our .bashrc
file to provide this feature:
alias backup='sudo rsync -av --delete /etc /home /usr/local /media/BigDisk/bac
kup'
Now all we have to do is attach our external drive and run the backup command to do the job.”

Excerpt From: William E. Shotts Jr. “The Linux Command Line.” iBooks.