rsnapshot

rsnapshot is a Perl-based backup tool that takes snapshots of filesystems using rsync and hard links. It creates periodic snapshots on local or remote machines with minimal disk space usage by keeping unchanged files as hard links across snapshots. The tool supports hourly, daily, weekly, and monthly backup intervals, and lets you configure retention policies for each level. You can back up directories from a single machine or multiple remote hosts over SSH. Setup involves editing a single config file to define backup source directories, snapshot intervals, and the destination root. rsnapshot runs from cron and handles file rotation automatically by promoting and removing snapshot directories. It does not compress or encrypt data by default, but you can pipe rsync through SSH with compression or tunnel it over VPN for security. The project was originally written by David Cantrell and is maintained by a small team of volunteers. It works on any Unix-like system with Perl, rsync, and hard link support. Because it relies on standard POSIX tools, rsnapshot fits well into existing sysadmin workflows without requiring a database or daemon.