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Lesson 3
Planning a Backup Strategy
6-31
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.
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