Rsync Explained !!!!

Rsync is a free software computer program for Unix and Linux like systems which synchronizes files and directories from one location to another while minimizing data transfer using delta encoding when appropriate.

How do I install rsync?

Use any one of the following commands to install rsync.

If you are using Debian or Ubuntu Linux, type the following command

# apt-get install rsync
OR
$ sudo apt-get install rsync

Always use rsync over ssh

Since rsync does not provide any security while transferring data it is recommended that you use rsync over ssh . This allows a secure remote connection. Now let us see some examples of rsync.

rsync command common options

• --delete : delete files that don't exist on sender (system)
• -v : Verbose (try -vv for more detailed information)
• -e "ssh options" : specify the ssh as remote shell
• -a : archive mode
• -r : recurse into directories
• -z : compress file data

Task : Copy file from a local computer to a remote server

Copy file from /www/backup.tar.gz to a remote server called openbsd.nixcraft.in
$ rsync -v -e ssh /www/backup.tar.gz jerry@openbsd.nixcraft.in:~Output:

Password:
sent 19099 bytes  received 36 bytes  1093.43 bytes/sec

total size is 19014  speedup is 0.99

Please note that symbol ~ indicate the users home directory (/home/jerry).

Task : Copy file from a remote server to a local computer

Copy file /home/jerry/webroot.txt from a remote server openbsd.nixcraft.in to a local computer /tmp directory:
$ rsync -v -e ssh jerry@openbsd.nixcraft.in:~/webroot.txt /tmp
Password

Task: Synchronize a local directory with a remote directory

$ rsync -r -a -v -e "ssh -l jerry" --delete openbsd.nixcraft.in:/webroot/ /local/webroot

Task: Synchronize a remote directory with a local directory

$ rsync -r -a -v -e "ssh -l jerry" --delete /local/webroot openbsd.nixcraft.in:/webroot 

Task: Synchronize a local directory with a remote rsync server

$ rsync -r -a -v --delete rsync://rsync.nixcraft.in/cvs /home/cvs

Task: Mirror a directory between my "old" and "new" web server/ftp

You can mirror a directory between my "old" (my.old.server.com) and "new" web server with the command (assuming that ssh keys are set for password less authentication)
$ rsync -zavrR --delete --links --rsh="ssh -l vivek" my.old.server.com:/home/lighttpd /home/lighttpd