Chapter 9. Backup Operations

Data backup involves transferring files from a system's primary storage to a different local or network device. Unlike simple file copying performed using the server operating system's file management system, backup programs (either those built into operating systems or purchased separately) perform file compression and, optionally, encryption during the backup. As a result, backed-up files must be restored before they can be used. Timely and well-organized data backups enable a business to recover from hardware failure, user error, or other threats to the contents of a server's hard disk.

While data backup is at least moderately important for individual PCs, it is a critical task for a server. Depending on the amount of new data generated and stored on a server, a weekly backup routine is often the absolute minimum recommended, and daily backups are often in order.

Backups provide additional benefits, as well. In addition to recording a copy of current information, backups can be used to move older and infrequently used data from hard disk to tape storage, giving the server's hard disk more capacity for newer and more frequently accessed information.

Historically, a popular method for backing up full hard disks or modified files has been using a tape backup drive. Although tape backups are no longer the only way to back up a server, tape backups remain the most popular method. This chapter discusses tape, removable-media drives such as Iomega REV drives, rewritable DVDs, and disk-to-disk backups to help you determine which type of storage technology is right for you.

This chapter examines the various types of tape and other backup drives on the market. It begins by looking at tape backup units, describing the capacities of different drives, the system requirements for installation and use of a tape drive, tape libraries, tape backup upgrades, backup strategies, and common backup applications.