Chapter 5: Backing up Windows Networks

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Backing up data is nothing new. In fact, originally data was stored on punch cards, punched paper strips, or magnetic tape and only loaded into the computer when the data was needed. But, as storage capacities have grown, together with the need for constant availability, backing up the data has become a more complex, yet even more vital undertaking. This chapter takes a look at various strategies for doing backups and restoring the data as needed, and it goes into depth regarding the backup functions that come with Windows, as well as the use of third-party software, mirroring, and off-site replication. Because many Windows-based sites now have some kind of Linux added into the mix, the chapter also addresses the special needs of backing up Linux in heterogeneous environments.

No More Simple Backups

Backing up was once a simple enough affair. At night or on the weekends, an administrator would run a tape on the servers, and desktops were backed up by copying files onto a few floppies, but with the explosion in drive storage over the past few years this is no longer possible. To backup a single 60-GB drive, for example, would require in excess of 40,000 floppies — not a practical solution. But, as the problem has grown, so have the available options for backing up data and ensuring its availability. Before taking a look at some of those solutions, a few terms should be defined:

• Backup — In general English usage, the concept of a backup means a reserve or substitute, something extra. When used in computing, it refers to a copy of the data on various types of storage media or a copy of the data kept for safety or emergency purposes.

• Restore — A restore means retrieving a file from the backup. If data loss occurs but the data has been backed up, that data can be restored from the backup.

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