Different RUN levels in Linux,Solaris and AIX

RedHat Linux - Run Levels 



 
0: Halt
1: Single user mode 2: Multiuser, without NFS 3: Full multiuser mode 4: Unused 5: X11 6: Reboot

 


Solaris - Run Level 

 
S: Single user state (useful for recovery) 0: Access Sun Firmware ( ok> prompt) 1: System administrator mode 2: Multi-user w/o NFS 3: Multi-user with NFS ( default run level) 4: Unused 5: Completely shutdown the