Linux的运行级别Runlevel

运行级别定义了系统启动之后的状态。内核启动之后会根据/inittab文件中的配置来确定运行级别。

分为如下几个运行级别：

0：halt

1：单用户、无网络

2：多用户、无网络

3：多用户、有网络

4：未定义，用户可定义

5：X11

6：重启




What is meaning of run level in Linux system? What are they?
Runlevel defines the state of the machine after boot. After the Linux kernel has booted, the init program reads the /etc/inittab file to determine the behavior for each runlevel. Unless the user specifies another value as a kernel boot parameter, the system will attempt to enter the default runlevel.
0 halts, 1 Single-User Mode without network. 2 Multi-User Mode without network. 3 Multi-User Mode with network. 4 Not used/User-definable For special purposes. 5 X11, 6, reboots.