Data storage technologies are imperfect. For this reason, it's wise to invest a small amount of time, effort, and expense in backing up your data, rather than risk spending crippling amounts of time, effort, and expense on recreating your data from scratch. If your primary data storage device dies, you'll have your backup, which can greatly reduce the recovery time. In a small office, backups may be performed without using the networksay, by using a portable tape backup unit and backing up each system directly. On a larger network, though, network backup tools can prove beneficial, and Linux can play a role in such systems. Linux can fit into the backup picture by providing an inexpensive platform to handle this task, along with tools of varying sophistication that can back up Linux, Unix, and Windows systems. Of course, backing up Linux itself (and other nonbackup Linux servers) is also important. Some Windows tools can do this, or you can use a Linux backup server to help out.
To begin this chapter, you should understand something of network backup strategies, such as what hardware is available, what types of backups are best suited to which situations, and so on. You must also understand how to back up a Linux system without using any network connections. This task is helpful in protecting the backup computer itself, and the skills involved transfer to some types of network backups. This chapter then looks at two specific network backup tools: Samba and the Advanced Maryland Automatic Network Disk Archiver (AMANDA).