Storing all of the information on your system to backup media is called
backing up your system. You back up your system so that you have a copy
of the information stored on it should it experience a major failure
that causes some or all of your files to be lost. If your system
experiences a failure, you can reload that information from your backup
media. Refer to subsequent chapters for complete instructions on
performing system backups and restoring files from backup media after a
system failure.
Planning, managing, and performing necessary system backups are,
perhaps, a system administrator's/operator's most important tasks.
Regularly scheduled, properly performed system backups guarantee that,
in the event of an unexpected system mishap, all information present on
the system at the time of the last backup is currently available.
If a system failure does occur, the amount of data lost depends directly upon
three factors:
How recently the last backup was performed.
The level of system activity since the last system backup.
The extent of the damage.
As a system administrator, you are responsible for establishing a backup
schedule that best meets the needs of your organization and all system
users. For example, the schedule may include saving all files in a
particular account every day, or more commonly, copying only those files
that have been added or modified since the last complete system backup.
You or a member of your staff are probably also responsible for actually
performing the backups. In addition to user files, you must be sure to
back up all system files since you may need to restore these files from
backup media if the system experiences problems.
