Syncing to a remote system is trivial if you have SSH access to the remote machine and rsync installed on both sides. Once you have SSH access verified between the two machines, you can sync the dir1 folder from earlier to a remote computer by using this syntax
rsync -a ~/dir1 username@remote_host:destination_directory
This is called a “push” operation because it pushes a directory from the local system to a remote system. The opposite operation is “pull”. It is used to sync a remote directory to the local system. If the dir1 were on the remote system instead of our local system, the syntax would be:
rsync -a username@remote_host:/home/username/dir1 place_to_sync_on_local_machine
Like cp and similar tools, the source is always the first argument, and the destination is always the second.
Useful Options for Rsync
Rsync provides many options for altering the default behavior of the utility. We have already discussed some of the more necessary flags.
If you are transferring files that have not already been compressed, like text files, you can reduce the network transfer by adding compression with the -z option:
rsync -az source destination
The -P flag is very helpful. It combines the flags --progress and --partial. The first of these gives you a progress bar for the transfers and the second allows you to resume interrupted transfers:
rsync -azP source destination
In order to keep two directories truly in sync, it is necessary to delete files from the destination directory if they are removed from the source. By default, rsync does not delete anything from the destination directory.
We can change this behavior with the --delete option. Before using this option, use the --dry-run option and do testing to prevent data loss:
rsync -a --delete source destination
rsync -a --exclude=pattern_to_exclude source destination
rsync -a --exclude=pattern_to_exclude --include=pattern_to_include source destination
rsync -a --delete --backup --backup-dir=/path/to/backups /path/to/source destination