Run Levels

The following run levels are specified for use by the "Default-Start:" and "Default-Stop:" specifiers as defined by the section Comment conventions for init scripts>. Many LSB run-time environments commonly use these run level definitions, and in the absence of other considerations, providers of run-time environments are strongly encouraged to follow this convention to provide consistency for system administrators who need to work with multiple distributions. However, it is not required that LSB-compliant run-time environments use these run levels; the distribution-provided install_initd script may map the run levels specified below to whatever distribution-specified run levels are most appropriate.

1single user mode
2multiuser with no network services exported
3normal/full multiuser
4reserved for local use, default is normal/full multiuser
5multiuser with xdm or equivalent