Linux Cookbook

Chapter 16. Backup and Recovery

Introduction

Making good backups is a fundamental chore, and one that is too often messy and inconvenient. This chapter covers using rsync and Mondo Rescue for robust, easy backups and, just as important, easy restores.

rsync is extremely efficient. It only transfers changes in files, and it can perform on-the-fly compression. It excels at keeping file trees sychronized; unlike a lot of backup software, it even mirrors deletions. Because of these features, rsync is the tool of choice for updating and mirroring web sites, CVS trees, and other large, complex file trees.

There are two ways to use rsync: over ssh , for authenticated login and transport; or by running it as a daemon to create public archives, which do not use ssh. Using ssh requires users to have login accounts on every machine for which they need rsync access. When rsync is run in daemon mode, you can use its built-in authentication methods to control access, so that users do not need login accounts on the rsync server.

Mondo Rescue is a great utility for creating a bootable system restore disk. Use it to make a snapshot of your current system configuration, and a bare-metal rebuild is as easy as booting to a CD or DVD. You’ll have all of your patches, configurations, and updates. Then pull your data from your rsync server, and you’re back in business in record time. Mondo can also be used for a complete system backup, all by itself.

Tape backups have long been a mainstay, because they ...