Editing Runlevel (section)

=== AIX ===
[[AIX (operating system)|AIX]] does not follow the [[System V]] R4 (SVR4) runlevel specification, with runlevels from 0 to 9 available, as well as from a to c (or h). 0 and 1 are reserved, 2 is the default normal multi-user mode and runlevels from 3 to 9 are free to be defined by the administrator. Runlevels from a to c (or h) allow the execution of processes in that runlevel without killing processes started in another.

{| class="wikitable"
|+AIX runlevels
|-
!ID
!Name
!Description
|-
|0
|
|reserved
|-
|1
|
|reserved
|-
|2
|Normal Multi-user mode
|default mode
|}

The S, s, M and m runlevels are not true runlevels, but are used to tell the init command to enter maintenance mode. When the system enters maintenance mode from another runlevel, only the system console is used as the terminal.