For years, tape drives have been the de facto choice for completely backing up a computer system. Ranging from less than a cent to five cents per megabyte, tape drives still provide the cheapest high-capacity backup storage solution available.

There are several different types of tape drives that allow storage capacities ranging from 4 GB to as much as 50 GB of uncompressed data (or 100 GB of compressed data) on a single cassette.

The biggest drawback? Data recovery is slow. Tape is not a random-access media, meaning that instead of pinpointing the data you want to access instantly, you have to wind through the tape to locate it.

However, tapes' low cost and high storage capacities have made them a top choice for many firms' backup strategies.

The most commonly used tape drives are DAT (Digital Audio Tape) and DLT (Digital Linear Tape).

DAT drives are especially well suited for small businesses that need to back up numerous small files. Using a 4 mm tape originally designed for digital audio players, DAT drives can handle 1 to 4 GB per cartridge. See Price Guide

Backup software
Most tape drives come equipped with software that allows unattended backups of a single computer or a small network. For larger networks, you generally have to buy third-party software that works with the backup drive and the network operating system.

Software must be able to handle problems during backup and recovery. It should allow recoveries to be made from any individual tape or disk, and should be tolerant of user mistakes, such as files that are left open, by alerting the user rather than crashing or aborting the backup.