In Linux, tasks can be configured to run automatically within a given
period of time and on given dates. Red Hat Linux comes preconfigured to run
certain system tasks to keep your system updated. For example, the slocate
database is updated daily. A system administrator can use automated tasks
to perform periodic backups, monitor the system, run custom scripts, and
more.
Cron is a daemon that can be used to execute scheduled tasks according
to a combination of the time, day of the month, month, day of the
week, and week.
Cron assumes that the system is on continuously. If the system is not on
when a task is scheduled it is not executed. To configure tasks based
on periods instead of exact times, see the section called Anacron.
To use the cron service, you must have the
vixie-cron RPM package installed. To determine if
the package is installed, use the command rpm -q
vixie-cron.
