The term runlevel refers to a mode of operation in Unix-like operating systems. Conventionally, seven runlevels exist, numbered from zero to six; though up to ten, from zero to nine, may be used.
S is sometimes used as a synonym for one of the levels. Only one "runlevel" is executed on bootup - run levels are not executed sequentially, i.e. either runlevel 2 OR 3 OR 4 is executed, not 2 then 3 then 4.
It can be changed using init command
#init 0
will Halt/Shut down the system.
Most of the Linux has following Runlevels
| Code | Description |
|---|---|
| 0 | Halt |
| 1 | Single-user text mode (without networking) |
| 2 | Not used (user-definable) |
| 3 | Full multi-user text mode |
| 4 | Not used (user-definable) |
| 5 | Full multi-user graphical mode (with an X-based login screen) |
| 6 | Reboot |
The
chkconfig utility updates and queries runlevel information for system servicesDebian GNU/Linux runlevels:
| Code | Description |
|---|---|
| S | Only run on boot (replaces /etc/rc.boot) |
| 0 | Halt |
| 1 | Single-user mode |
| 2-5 | Full Multi-user with console logins and display manager if installed |
| 6 | Reboot |
No comments:
Post a Comment
Any Suggestion or Complain