PUBLIC MARKS from sledge with tag backup

This document describes a method for generating automatic rotating "snapshot"-style backups on a Unix-based system, with specific examples drawn from the author's GNU/Linux experience. Snapshot backups are a feature of some high-end industrial file servers; they create the illusion of multiple, full backups per day without the space or processing overhead. All of the snapshots are read-only, and are accessible directly by users as special system directories. It is often possible to store several hours, days, and even weeks' worth of snapshots with slightly more than 2x storage. This method, while not as space-efficient as some of the proprietary technologies (which, using special copy-on-write filesystems, can operate on slightly more than 1x storage), makes use of only standard file utilities and the common rsync program, which is installed by default on most Linux distributions. Properly configured, the method can also protect against hard disk failure, root compromises, or even back up a network of heterogeneous desktops automatically.

cwRsync is a yet another packaging of Rsync and Cygwin. You can use cwRsync for fast remote file backup and synchronization.

This article describes a complete system for creating a centralised backup system, complete with strong encryption. Incremental backups are used to minimize the bandwidth, and time, used.

RIBS is an incremental backup system written in PHP which utilizes some common *nix programs (specifically rsync, ssh and cp). Incremental backups mean frequent backups can be done (i.e. hourly) with only around 2x the space of the full backup.