Lesson 3

Planning a Backup Strategy

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Lesson 3: Planning a Backup Strategy

Performing regular backups is one of the most basic functions of the network admin-

istrator. Unlike most of the key components in a computer, hard drives have parts that

move at high speeds, working at very close tolerances. As a result, hard drive failures

are relatively common, and you must prepare for them by regularly saving your data

on another storage medium.

Off the Record The most common analogy used to describe the relationship between a

hard drive’s platters (where the data is stored) and its heads (which read and write data to

the platters) is that of a 747 airliner flying at 500 miles an hour, five feet above the ground.

When you consider this, it is amazing that hard drives work as well and as long as they do.

After this lesson, you will be able to

■ Describe the elements of a backup strategy and their functions

■ Understand the difference between full, incremental, and differential backup jobs

■ List the steps involved in creating a backup plan

Estimated lesson time: 30 minutes

Understanding Network Backups

A network backup solution consists of three elements: one or more backup drives, a

backup software product, and a backup plan that details the use of the other two items.

Backup Hardware

The storage medium that most administrators choose for backing up their networks is

magnetic tape. Magnetic tape drives have high capacities, low media costs, and are a

reliable means of long-term data storage. High capacity is a major requirement for a

backup medium, because administrators usually like to create unattended backup solu-

tions that can run at night, or while the business is closed. The higher the capacity of

the storage device, the fewer times an administrator has to change the medium to com-

plete the backup.

Off the Record Many removable storage devices that would otherwise be acceptable

backup media, such as Compact Disk-Recordable drives (CD-Rs) and Zip cartridges, are

almost never used for backups, because an administrator would have to hang around the

office all night swapping new disks or cartridges into the drive.