The data backup and archive needs of a personal computer can be overwhelming. People with large hard drives and numerous applications installed and those who generate a large amount of data might need to back up their computers on a weekly or even a daily basis.

In addition, a critical need on today's PCs is data storage space. Sometimes it seems as though the storage requirements of a PC can never be satisfied. On nearly any PC used for business, study, or even fun, the amount of software installed can quickly overwhelm even a large hard drive.

To save space on the primary storage devices, you can archive infrequently used data to another storage medium. Depending on the method you use for archiving data to secondary storage, you might be able to read the data directly from the device, or you might need to restore the data to the drive before you can access it.

If you copy data to the drive with drag-and-drop, the data can be read from the media directly. However, if you use a backup program to create the backup, you will need to use that same program to access the data and restore it to a drive before it can be reused.

Historically, a popular method for backing up full hard disks or modified files has been a tape backup drive. This section focuses on current tape backup drive technologies to help you determine whether this type of storage technology is right for you.

Tape backup drives are the most simple and efficient device for creating a full backup of your hard disk if the tape is large enough. With a tape backup drive installed in your computer, you insert a tape into the drive, start your backup software, and select the drive and files you want to back up.

The backup software copies your selected files onto the tape while you attend to other business. Later, when you need to retrieve some or all of the files on the backup tape, you insert the tape in the drive, start your backup program, and select the files you want to restore. The tape backup drive takes care of the rest of the job.

Hard-Disk-Based Alternatives to Tape Backup

Before you decide to adopt a tape backup as your backup strategy, keep the following alternatives in mind:

• External hard drives. Maxtor, Western Digital, SimpleTech, and others have developed external hard drives with capacities ranging from 20GB up to 200GB. These drives attach through USB 1.1, USB 2.0, or IEEE-1394a ports and can be used for data backup with backup software or drag-and-drop file copying.

The Maxtor Personal Storage 5000 family has an exclusive OneTouch feature that starts the file copying process automatically and can be used to launch Dantz Retrospect Express backup software.

• RAID arrays. By connecting identical hard disks to a RAID array using RAID 1 data mirroring or RAID 5 data striping with parity, your data is automatically backed up as soon as it is created. RAID arrays were once used strictly for SCSI drives on networks because of their high cost.

However, recent developments in high-performance, low-cost, RAID 1-compatible ATA host adapters on motherboards and add-on cards make this another useful backup strategy to consider. RAID 5 arrays generally require a separate host adapter.

Disadvantages of Tape Backup Drives

Many computer users who once used tape backups for data backup purposes have turned to other technologies for the following reasons:

• Creating a tape backup copy of files or of a drive requires the use of a special backup program in almost all cases. A few tape drives allow drive letter access to at least part of the tape capacity, but this feature is far from universal.

• Retrieving data from most tape backup drives requires that the data files be restored to the hard disk. Other types of backup storage can be treated as a drive letter for direct use from the media.

• Tape backups store and retrieve data sequentially. The last file backed up can't be accessed until the rest of the tape is read; other types of backup storage use random access, which enables any file on the device to be located and used in mere seconds.

• Low-cost tape backups using QIC (Quarter Inch Committee), QIC-Wide, or Travan technology once had little problem keeping up with increases in hard disk capacity and once sold for prices comparable to or less than the hard disks they protected.

Today's hard disks have capacities of 20GB–200GB and are far less expensive than most comparably sized tape backups. As a result, more expensive, higher-capacity tape drives are needed to achieve single-cartridge backups.

• Newer backup and restore techniques, such as drive imaging/ghosting, rival the ease of use of tape backups and permit data restoration with lower-cost optical storage devices such as CD-RW or rewritable DVD drives. These alternatives are particularly useful if only a few GB of data needs to be backed up on a continuing basis.

For these reasons, the once-unassailable position of a tape backup drive as being the must-have data protection accessory is no longer a secure one; plenty of rivals to tape backups are on the market.

However, if you can afford a high-quality DDS or AIT tape drive, you can get a high-performance and high-reliability solution because these same drives are used in the demanding roles of network backup.

Advantages to Tape Backup Drives

Although tape backup drives are no longer the one-size-fits-all panacea for all types of bigger-than-floppy storage problems, they have their place in keeping your data safe. Following are several good reasons for using tape backup drives:

• Tape backups are a true one-cartridge backup process for individual client PCs, standalone computers, or network servers when high-capacity tape drives and cartridges are used. Anytime multiple tapes or disks must be used to make a backup, the chances of backup failure increase.

• If you or your company has made previous backup tapes, you must keep a tape drive to access that data or perform a restore from it. Tape backup drives are necessary if you need to restore from previously made backup tapes.

• If you want an easy media rotation method for preserving multiple full-system backups, tape backup drives are a good choice.

In general, tape drives are used where high capacity and high reliability are paramount. They can be expensive initially but are extremely inexpensive when you factor in the low cost of the media over time.