PLD system can be run in several runlevels:
|Runlevel 1||Single user mode. Used by administrator for rescue/emergency/system maintenance reasons.|
|Runlevel 2||Multiuser level, but without Network File System|
|Runlevel 3||Normal multiuser level. This is most commonly used runlevel.|
|Runlevel 5||Normal multiuser level with X Window environment started by default. This is popular choice for workstations.|
|Single||Single user mode - used in emergency situations. It runs less services than runlevel 1.|
System boots up in default runlevel that is defined in /etc/inittab which is usually 3 or 5. Current runlevel can be changed with telinit command. For example, if system is running level 3, issuing telinit 2 brings it to level 2 (as a consequence, NFS subsystems will be stopped).