Can any one tell what is default run level in Linux

Senthilv · 06-08-2013, 12:52 PM

Hai All,

I just want to known what is the default run level in linux?

tronayne · 06-08-2013, 01:12 PM

There are two: run level 3 is the text console, run level 4 is the default for a GUI log in window.

Here's a list of the run levels in Slackware (from /etc/inittab), they should be comparable on other distributions:

Code:

#   0 = halt
#   1 = single user mode
#   2 = unused (but configured the same as runlevel 3)
#   3 = multiuser mode (default Slackware runlevel)
#   4 = X11 with KDM/GDM/XDM (session managers)
#   5 = unused (but configured the same as runlevel 3)
#   6 = reboot

Hope this helps some.

Timothy Miller · 06-08-2013, 01:51 PM

And then the Red Hat levels are:

Code:

0 — Halt
1 — Single-user text mode
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

Every system has the default runlevel set by the admin, so it can change from system to system. I use 4 (slackware-type) or 5 (Red Hat-type) most often except on my old server (RIP), which used 3.

273 · 06-08-2013, 02:02 PM

Debian is different again (this may apply to Ubuntu and Mint also, but I don't know for sure).

Code:

# Runlevel 0 is halt.
# Runlevel 1 is single-user.
# Runlevels 2-5 are multi-user.
# Runlevel 6 is reboot.

Timothy Miller · 06-08-2013, 02:25 PM

Yeah, while I love Debian, their runlevels seem absolutely arbitrary...

273 · 06-08-2013, 02:34 PM

Quote:

Originally Posted by Timothy Miller

Yeah, while I love Debian, their runlevels seem absolutely arbitrary...

You're telling me. I hate to admit but I'd not checked the runlevels in Debian before, since I always boot into a GUI, so I hadn't realised how arbitrary they were.

syg00 · 06-08-2013, 06:22 PM

Can I perhaps toss systemd into the discussion ....

Runlevels are probably destined to become moot - even for Debian.

Habitual · 06-08-2013, 09:19 PM

Quote:

Originally Posted by Senthilv

Hai All,

I just want to known what is the default run level in linux?

in Linux what?
http://en.wikipedia.org/wiki/Telinit#Default_runlevels

Senthilv · 06-08-2013, 09:42 PM

Thanks MR.Habitual

Z038 · 06-09-2013, 01:12 AM

Quote:

Originally Posted by syg00

Can I perhaps toss systemd into the discussion ....

Runlevels are probably destined to become moot - even for Debian.

In systemd, do you know how one specifies whether to boot to single user text mode, multiuser text mode, or graphical session manager mode?

syg00 · 06-09-2013, 03:01 AM

Systemd uses targets - some Fedora doco here.

As usual, the Arch wiki also has some good doco.

Z038 · 06-09-2013, 09:25 AM

Thanks, syg00. systemd sounds complex, but intriguing. I may have to install Fedora on one of my systems just to see how it works.

jlinkels · 06-09-2013, 01:15 PM

Quote:

Originally Posted by Timothy Miller

Yeah, while I love Debian, their runlevels seem absolutely arbitrary...

Runlevels are arbitrary. IIRC there are several live distros using several more levels for several other flavors of the running environment. It is just a matter of configuration and configuration have been enumerated.

However, for the sake of uniformity it would have been better if a de facto standard had evolved in the course of time. I remember switching from RH to Debian as a newbie and heck I could not understand why Debian would not show X runlevel 5.

jlinkels

chrism01 · 06-09-2013, 09:28 PM

@OP: just to emphasise/extend tronayne's comment, /etc/inittab lists all the available runlevels, what they mean and what the the current default is; see last line

Code:

# Default runlevel. The runlevels used are:
#   0 - halt (Do NOT set initdefault to this)
#   1 - Single user mode
#   2 - Multiuser, without NFS (The same as 3, if you do not have networking)
#   3 - Full multiuser mode
#   4 - unused
#   5 - X11
#   6 - reboot (Do NOT set initdefault to this)
# 
id:5:initdefault:

syg00 · 06-09-2013, 11:12 PM

Or, you may see something like this ...

Quote:

# inittab is no longer used when using systemd.

As always, Linux is about choice - doesn't pay to presume too much.