Introduction to rsync, a free powerful tool for syncing data

Rsync (Remote Sync) is a command for copying and synchronizing files and directories remotely as well. You can easily mirror your data by comparing source and destination.
For a typical transfer, rsync compares filenames and file timestamps on the source and destination directory trees to assess which files should be transferred.
Also rsync can effectively resume transfers that have been halted or interrupted.

Advantages of Rsync:

• It efficiently copies and sync files to or from a remote system.
• Supports copying links, devices, owners, groups and permissions.
• It’s faster than scp (Secure Copy).
• Rsync consumes less bandwidth

How to install Rsync:
By default rsync package is bundled with OS, else you need to use your package mangers like yum, apt-get to install rsync.

Basic Syntax:
rsync [options] source destination

Some common options used with rsync commands:
-v : verbose
-a : archive mode
-z : compress file data
-h : human-readable
-r : copies data recursively 

To Sync two data centers with delete options : rsync -avz --delete 11.0.2.2:/data/ /data

Here are some of the examples, have a try in a test environment or use a dry run option:

1. Copy/Sync a File on a Local Computer
[root@shvijai]# rsync -zvh myfilesp.tar /tmp/backups/

2. Copy a Directory from Local Server to a Remote Server
[root@shvijai]$ rsync -avz www/ root@192.168.0.101:/home/

3. Copy/Sync a Remote Directory to a Local Machine
[root@shvijai]# rsync -avzh root@192.168.0.100:/home/shvijai/www-files /tmp/mywebsite

4. Copy a File from a Remote Server to a Local Server with SSH
[root@shvijai]# rsync -avzhe ssh root@192.168.0.100:/root/backup.log /tmp/

5. Copy a File from a Local Server to a Remote Server with SSH
[root@shvijai]# rsync -avzhe ssh mybackup.tar root@192.168.0.100:/mybackups/

6. Use of –include and –exclude Options
[root@shvijai]# rsync -avze ssh --include 'R*' --exclude '*' root@192.168.0.101:/var/lib/rpm/ /mnt/rpm

7. Use of –delete Option
[root@shvijai]# rsync -avz --delete root@192.168.0.100:/var/lib/rpm/ .

8. Automatically Delete source Files after successful Transfer
[root@shvijai]# rsync --remove-source-files -zvh mybackup.tar /mnt/mybackups/

9. Do a Dry Run with rsync
root@shvijai]# rsync --dry-run --remove-source-files -zvh mybackup.tar /mnt/mybackups/