The Rsync Command

Summary

Rsync is a command-line tool designed for file and directory synchronization.

Unique to the rysnc command is its use of a delta-transfer algorithm. Before transferring, rsync compares the source and destination files. By default, it identifies changes by checking modification times and file sizes. If a file has been modified, the algorithm determines which specific parts of the file have changed and sends only those differences.

Basic command structure

For all descriptions below, the dollar sign indicates that BASH command prompt.

$ rsync [options] [source] [destination]

OPTIONS: These are flags that modify rsync’s behavior.`

SOURCE: The path to the file or directory you want to copy or synchronize. This can be local or remote (e.g., user@remotehost:/path/to/source).`

DESTINATION: The path where you want to copy or synchronize the files. This can also be local or remote.`

Possible Flags

`-a`

The -a (archive mode) flag is recommended for most use cases because it syncs recursively while preserving permissions, ownership, and modification times.

`-v`

The -v (verbose) flag shows detailed information about the transfer process.

`-z`

The -z (compress) flag compresses data during transfer, useful for remote operations.

`-b`

The -b (backup) flag makes backups of files that are going to be overwritten or deleted during synchronization.

`-P`

The -P combines –progress (shows transfer progress) and –partial (allows resuming interrupted transfers).

`-n`

The -n (dry run) flag previews outcomes of rysnc without actually making any changes to files. Useful for testing.

Output

The rsync command differs in outputs, depending on the options you decide to use:

Note: The following command was done using my remote server. Files and folders are all from Class 5, and for the sake of this exercise, I have created an “rsyncfolder” (in my remote server).

Output with -a, -v -P flags, for local synchronization (archive mode, verbose, progress):

screenshot of -avP outputs

In this example, I used rsync to synchronize “Donation-demo” folder within my remote server, into another new folder titled “rsyncfolder.”

The results can be seen here, where all my files from the “Donation-demo” folder are now in “rsyncfolder.”

screenshot of -avP server results

Output with -a, -v -P flags, for local server to remote server synchronization (archive mode, verbose, progress):

screenshot of local to remote -avP outputs

In this example, I used rsync to synchronize the “DigLit_rsync_screenshots” folder from my local server to my remote server.

The results can be seen here, where after logging onto my remote server, I could see all my files listed out, including the “DigLit_rsync_screenshots” folder.