run levels description

The Following points shows the meaning of each run level :

• on LINUX-UBUTNU/DEBIAN:

0 – halt
1 – single user
2 – multiuser (default)
3 – same as 2
4 – same as 2
5 – same as 2
6 – reboot

• on IBM-AIX:

0 – reserved
1 – reserved 2 – multiuser mode with NFS
3 – user defined
4 – user defined
5 – user defined
6 – user defined
7-9 – user defined

• on LINUX-REDHAT:

0 – halt
1 – single user
2 – multiuser (no networking)
3 – multiuser (networking)
4 – unused
5 – GUI
6 – reboot

• on HP-UX:

0 – halt
1 – single users
2 – multiuser (networking)
3 – multiuser (networking, NFS, and CDE GUI) (default)
4 – multiuser (netwrking, NFS, and VUE GUI)
5 – n/a
6 – n/a

• on SUN-SOLARIS:

0 – shutdown
1 – single user
2 – n/a
3 – Multi-user
4 – n/a
5 – power off
6 – reboot