Solaris and Linux Runlevel

Default Linux Run Level: Total 7 Run Level

RunLevel 0: Halt System – To shutdown the system
RunLevel 1: Single user mode
RunLevel 2: Basic multi user mode without NFS
RunLevel 3: Full multi user mode (text based)
RunLevel 4: unused
RunLevel 5: Multi user mode with Graphical User Interface
RunLevel 6: Reboot System

Default Solaris Run Level: Total 8 Run Level

RunLevel S: Single user state (useful for recovery)

RunLevel 0: Access Sun Firmware (ok> prompt)

RunLevel 1: System administrator mode

RunLevel 2: Multi-user w/o NFS

RunLevel 3: Multi-user with NFS

RunLevel 4: Unused

RunLevel 5: Completely shutdown the host (like performing a power-off)

RunLevel 6: Reboot but depend upon initdefault entry in /etc/inittab