[ubuntu-us-mi] Booting Ubuntu

Robert Citek robert.citek at gmail.com
Sat Jun 7 06:59:06 BST 2008

On Fri, Jun 6, 2008 at 1:58 PM, Flavio daCosta <flav at binaryservice.com> wrote:
> On 06/06/2008 01:54 PM, Robert Citek wrote:
>> I'm guessing then that the third part needs to be modified to say
>> upstart instead of /sbin/init.  If so, where is upstart?
> Wherever you want it, but in Ubuntu /sbin/init is upstart.

Ah, I see.  There is no program called 'upstart'.  Instead, /sbin/init
start the upstart way instead of the sysV way.

> Spend some time to go through the site, there are some decent docs on
> there.  (A while back some of the examples didn't work as advertised but
>  I think it's stabilized now.)  Also some nice explanations/examples in
> the authors blog: http://www.netsplit.com/

So the first three section of 'man boot' still hold.  What's not clear
is what happens next.  Here's an excerpt from 'man boot':

init and inittab
  When init starts it reads /etc/inittab for further instructions.
This file defines what should be run in different run-levels.

  This  gives  the system administrator an easy management scheme,
where each run-level is associated with a set of services (e.g: S is
single-user, on 2 most network services start, etc.).  The
administrator may change the current run-level via init(8) and query
the current run-level via  runlevel(8).

  However,  since  it  is  not convenient to manage individual
services by editing this file, inittab only bootstraps a set of
scripts that actuallystart/stop the individual services.

That section of the man page seems to differ from what actually
happens using upstart.  For example, there is no more /etc/inittab.
Yet, there still seems remain something of the concept of runlevels.
That is, I can type the command 'runlevel' and get an answer.  I can
also change runlevels with 'telinit', e.g. 'telinit 6' to reboot.  And
I can still modify how scripts start and stop by changing the symlinks
in /etc/rc?.d/  directories.

What I have not been able to do is temporarily change my runlevel at
startup.  That is, in the past I could boot into runlevel 5 by simply
adding a 5 to the end of a grub kernel line.  That doesn't work.  For

$ cat /proc/cmdline
root=UUID=538f72a2-fbc0-454f-a058-32d1a0cae8b3 ro 5

$ runlevel
N 2

As the runlevel command shows, Ubuntu still booted into runlevel 2.

So, how does one boot into runlevel 5 or is the concept of runlevels
somehow altered or deprecated?

- Robert

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