答: 一共有七种运行级别,如下:
- 0 – System halt i.e the system can be safely powered off with no activity.
- 1 – Single user mode.
- 2 – Multiple user mode with no NFS(network file system).
- 3 – Multiple user mode under the command line interface and not under the graphical user interface.
- 4 – User-definable.
- 5 – Multiple user mode under GUI (graphical user interface) and this is the standard runlevel for most of the LINUX based systems.
- 6 – Reboot which is used to restart the system