Run Levels and their meanings:
Value | Explanation |
---|---|
0 | Halt |
1 | Single-user text mode |
2 | Full multi-user with no networking |
3 | Full multi-user, console logins only |
4 | Not used (user-definable) |
5 | Full multi-user graphical mode (with an X-based login screen) |
6 | Reboot (Do NOT set initdefault to this) |
CentOS 6:
List all services and their run levels:
chkconfig --list
chkconfig httpd onThis turns on run levels 2, 3 and 4
Turning on levels 3,4 and 5
chkconfig --level 345 httpd on
chkconfig --level 5 httpd off