runlevel in Linux and Solaris and AIX

运行级别对于系统使用来说应该是一个很重要的基本概念，原来一直使用Linux，现在又用Solaris和AIX，一下模糊了，他们对runlevel的定义有些许不同，现本人搜集了哈，做个比较。

runlevel

Linux

Solaris

halt (Do NOT set initdefault to /etc/inittal "initlevel" entry)

halt

1

Single user mode

2

Multiuser, without NFS (The same as 3, if you do not have networking)

multiuser, unshare net

3

Full multiuser mode

multiuser, deafult

4

unused

5

X11

halt, power off

6

reboot (Do NOT set initdefault to this)

reboot to level 3

S

None

equal “init 1”, “boot -s”

      AIX:

      "AIX does not follow the System V R4 (SVR4) run level specification, with run levels from 0 to 9 available, as well as from a to c. 0 and 1 are reserved, 2 is the default normal multiuser mode and run levels from 3 to 9 are free to be defined by the administrator. Run levels from a to c allow the execution of processes in that run level without killing processes started in another."

本文转自 xkdcc 51CTO博客，原文链接：http://blog.51cto.com/brantc/116008，如需转载请自行联系原作者