The software described in this documentation is either in Extended Support or Sustaining Support. See https://www.oracle.com/us/support/library/enterprise-linux-support-policies-069172.pdf for more information.
Oracle recommends that you upgrade the software described by this documentation as soon as possible.
Run levels allow you to start a system with only the services that
are required for a specific purpose. For example, a server can run
more efficiently at run level 3, because it does not run the X
Window System at that run level. It is best to perform
diagnostics, backups, and upgrades at run level 1 when only
root can use the system. Each run level defines
the services that init stops or starts. For
example, run level 3 starts network services and run level 5
starts the X Window System, whereas run level 1 stops both of
these services.
The following run levels are defined by default under Oracle Linux:
-
0 Halts the system.
-
1 Single-user text mode.
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2 Full multiuser text mode without NFS support.
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3 Full multiuser text mode with NFS support.
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4 Not used, but can be user defined.
-
5 Full multiuser graphical mode with an X-based login screen.
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6 Reboots the system.