What does the rsync command do in Linux?

The rsync command is a versatile tool for synchronizing files and directories, locally and remotely. It's known for its delta-transfer algorithm, which minimizes data transfer by only sending the differences between files.

How do I use rsync to copy files?

Use 'rsync -av source/ destination/' to copy files and directories recursively, preserving permissions, timestamps, and symbolic links. For example: rsync -av /home/user/docs/ /mnt/backup/docs/.

Can rsync be used for remote backups?

Yes, rsync is commonly used for remote backups. You can specify a remote host and path using the syntax 'rsync -avz source/ user@remote_host:/path/to/destination/'.

rsync Command

The rsync command is a powerful and versatile command-line utility for synchronizing files and directories between two locations, either locally or remotely. It's widely used for backups, mirroring, and efficient data transfer due to its delta-transfer algorithm, which only transfers the differences between files.

Syntax

rsync [OPTION]... SOURCE [DESTINATION]

Description

rsync is a fast and extraordinarily versatile file copying tool. It can copy locally, to/from a remote shell, or to/from a remote rsync daemon. It offers a large number of options that control every aspect of its behavior and permit a wide range of flexible transfer modes.

Key features include:

Efficient delta-transfer algorithm (only sends changed parts of files)
Preserves permissions, ownership, timestamps, and symbolic links
Supports local and remote synchronization (via SSH or rsync daemon)
Can be used for backups, mirroring, and incremental transfers

Common Options

Option	Description
`-a`, `--archive`	Archive mode; equals -rlptgoD (recursive, links, perms, times, group, owner, devices)
`-v`, `--verbose`	Increase verbosity
`-z`, `--compress`	Compress file data during the transfer
`-h`, `--human-readable`	Output numbers in a human-readable format
`--delete`	Delete extraneous files from destination dirs (removes files in destination that are not in source)
`-r`, `--recursive`	Recurse into directories
`-u`, `--update`	Skip files that are newer on the receiver
`-P`	Equivalent to --partial --progress (show progress during transfer)

Examples

Synchronize local directories

rsync -av /path/to/source/ /path/to/destination/

Synchronizes the contents of 'source' directory to 'destination' directory, preserving attributes.

Synchronize local to remote via SSH

rsync -avz /path/to/local/ user@remote_host:/path/to/remote/

Copies files from local to remote, compressing data during transfer.

Synchronize remote to local via SSH

rsync -avz user@remote_host:/path/to/remote/ /path/to/local/

Pulls files from remote to local, compressing data during transfer.

Delete files in destination that are not in source

rsync -av --delete /path/to/source/ /path/to/destination/

Synchronizes directories and deletes files in destination that are not present in source.

Show progress during transfer

rsync -avP /path/to/source/ /path/to/destination/

Synchronizes directories and shows progress for each file.