Rsync File Transfer & Synchronization in Linux – Complete Guide

Rsync is a powerful tool for transferring and synchronizing files between systems. It is commonly used for backups, file mirroring, and updating files between local directories or remote servers. Rsync reduces data transfer by copying only the differences between the source and destination files. Due to its speed, flexibility, and extensive options, it is a preferred choice for system administrators and developers.

Prerequisites

Ensure you have a Linux-based workstation with non-root sudo access and sufficient disk space for handling large file transfers.

Installing Rsync on Linux

Rsync is available in the official repositories of most Linux distributions and is often pre-installed. Use the commands below to install Rsync based on your Linux distribution.

Install Rsync using APT

$ sudo apt install rsync

Install Rsync using PKG

$ sudo pkg install rsync

Install Rsync using Pacman

$ sudo pacman -S rsync

Install Rsync using DNF

$ sudo dnf install rsync

Install Rsync using YUM

$ sudo yum install rsync

Rsync Command Syntax

Rsync uses the following syntax:

rsync [OPTION] SRC DEST

The Rsync command consists of the following components:

• [OPTION]: Specifies various flags or parameters used to control the Rsync operation.
• SRC: Denotes the source files and directories that need to be synchronized.
• For remote transfers over SSH, use USER@HOST:SRC as the source path.
• DEST: Indicates the target location where files or directories will be synchronized.
• For remote synchronization over SSH, specify USER@HOST:DEST as the destination path.

Rsync Command Options

Below is a list of commonly used Rsync command options along with their descriptions:

Transferring Local Files Using Rsync

The following steps explain how to move files between directories using Rsync.

To copy file1, file2, and file3 into a directory called dest, use the Rsync command. The last parameter in Rsync always refers to the destination, so be cautious to avoid unintentional overwrites.

rsync file1 file2 file3 dest

• file1 file2 file3: Files being copied.
• dest: Target directory for storing the copied files.

To confirm the transfer, use the ls command:

ls dest/

Expected output:

./dest/file1
./dest/file2
./dest/file3

Copying Directories Locally

By default, Rsync does not automatically copy all contents inside a directory. To copy directories recursively while maintaining file attributes such as timestamps, permissions, and symbolic links, use the -a (archive) flag.

Copy the previously created dest directory:

rsync -a dest/ dest-copy

• -a: Enables archive mode for recursive copying while keeping file attributes intact.
• dest/: Source directory (a trailing / ensures only contents are copied, not the directory itself).
• dest-copy: Destination directory.

Verify the copied directory using:

ls dest-copy/

Expected output:

./dest-copy/file1
./dest-copy/file2
./dest-copy/file3

Excluding Files or Directories in Rsync

Use the --exclude option in Rsync to avoid copying certain files or directories.

The following command copies everything from the current directory while omitting file2 and any directory that starts with dest:

rsync -a --exclude 'file2' --exclude 'dest*' . output

• -a: Enables archive mode.
• --exclude 'file2': Skips files named file2.
• --exclude 'dest*': Excludes all files and directories that begin with dest.
• .: Specifies the current directory as the source.
• output: Target directory.

Syncing Files to a Remote Server with Rsync

To synchronize your files and directories with a remote system using SSH, follow these steps.

Transfer Files to a Remote Machine

Use the Rsync command below to copy files and directories to a remote server:

rsync -hazvP --delete --stats . user@192.0.2.1:synced_from_local

• -h: Displays file sizes in a human-readable format.
• -a: Activates archive mode to retain file attributes.
• -z: Compresses files during transfer to optimize speed.
• -v: Enables verbose mode for detailed output.
• -P: Shows progress updates and resumes partial transfers if interrupted.
• --delete: Removes files from the destination that no longer exist in the source.
• --stats: Provides a summary of transfer details.
• .: Indicates the current directory as the source.
• user@192.0.2.1:synced_from_local: Specifies the remote machine as the target destination, structured as follows:
  • user: Username for logging into the remote machine.
  • 192.0.2.1: IP address of the remote system.
  • synced_from_local: Destination directory on the remote machine.

Accessing the Remote Server

After syncing, connect to the remote machine via SSH to verify the transferred files:

ssh user@192.0.2.1

Checking Synced Files

Run the following command on the remote server to confirm that the files were successfully transferred:

ls synced_from_local/

Expected directory structure after synchronization:

synced_from_local/dest-copy/file1
synced_from_local/dest-copy/file2
synced_from_local/dest-copy/file3
synced_from_local/dest/file1
synced_from_local/dest/file2
synced_from_local/dest/file3
synced_from_local/file1
synced_from_local/file2
synced_from_local/file3
synced_from_local/output/file1
synced_from_local/output/file3

Caution When Using the --delete Option

Be careful when utilizing the --delete flag, as it will permanently remove files from the destination if they are not present in the source. To prevent unintended data loss, always conduct a test run before executing the command:

rsync -a --delete --dry-run SRC DEST

Conclusion

In this tutorial, you installed Rsync, learned how to synchronize files locally and remotely, and used essential features like --exclude and recursive copying. Always double-check Rsync commands, particularly when using --delete. For more details, run:

man rsync