rsync-backup

Creates a backup of a directory, with incremental hard-link copies up to any number of times.

Overview

• Fast incremental backups using Rsync.
• Multiple backups with the same command (cronjob-friendly).
• Preserves disk space using hard links from older backups.

Usage

rsync-backup.sh <src> <dst> <num_recycle>

• src the source directory to backup;
• dst the destination directory to store the backups;
• num_recycle the maximum number of copies to store.

One run will only create one backup. Consecutive runs with the same command will create new copies and recycle old copies with hard links, not exceeding the maximum number of copies.

Backup structure

The backup copies will be stored in the destination directory as backup.<number>, starting with <number> is 0. Each backup directory contains a date.txt file with the backup date and a copy of the source directory.

Example: running rsync-backup.sh source target 3 3+ times will result in the following directory structure:

target
	backup.0
		source
		date.txt
	backup.1
		source
		date.txt
	backup.2
		source
		date.txt

All following runs of the same command will recycle these directories and shift them 'up', meaning the most recent backup is always in backup.0.