rsync examples

If you want to remote-copy a directory or files from one host to another, making a particular backup, you can use rsync, which is designed for network backups of particular directories or files, intelligently copying only those files that have been changed, rather than the contents of an entire directory. In archive mode, it can preserve the original ownership and permissions, providing corresponding users exist on the host system.


The following example copies the /home/george/myproject directory to the /backup directory on the host rabbit, creating a corresponding myproject subdirectory. The -t specifies that this is a transfer. The remote host is referenced with an attached colon, rabbit:.

rsync -t /home/george/myproject rabbit:/backup

If, instead, you want to preserve the ownership and permissions of the files as well as include all subdirectories, you use the -a (archive) option. Adding a -z option will compress the file. The -v option provides a verbose mode (you can leave this out if you wish):


rsync -avz /home/george/myproject rabbit:/backup


The -a option is the equivalent to the following options: r (recursive), l (preserve symbolic links), p (permissions), g (groups), o (owner), t (times), and D (preserve device and special files). The -a option does not preserve hard links, as this can be time consuming.

If you want hard links preserved, you need to add the -H option:

rsync -avzH /home/george/myproject rabbit:/backup



The rsync command is configured to use Secure Shell (SSH) remote shell by default. You can specify it or an alternate remote shell to use with the -e option. For secure transmission, you can encrypt the copy operation with ssh. Either use the -e ssh option or set the RSYNC_RSH variable to ssh:

rsync -avz -e ssh /home/george/myproject rabbit:/backup/myproject


You can also run rsync as a server daemon. This will allow remote users to sync copies of files on your system with versions on their own, transferring only changed files rather than entire directories. Many mirror and software FTP sites operate as rsync servers, letting you update files without having to download the full versions again. Configuration information for rsync as a server is kept in the /etc/rsyncd.conf file. Check the man page documentation for rsyncd.conf for details on how to configure the rsync server. You can start, restart, and shut down the rsync server using the /etc/init.d/rsync script: sudo /etc/init.d/rsync restart


TIP

Though it is designed for copying between hosts, you can also use rsync to make copies within your own system, usually to a directory in another partition or hard drive. In fact, you can use rsync in eight different ways. Check the rsync man page for detailed descriptions of each.





we can add a crontab entry like this:-

crontab -e

35 8 * * * rsync -pavc /home/mydir /backup



source richard petersen