[gentoo-user] booting into single mode

[gentoo-user] booting into single mode

[Philip Webb]

Is it still possible to boot into 'single' mode,
ie directly into a no-login root system (for emergencies) ?

The kernel dox suggest this should work in Lilo

  image = /boot/kernel-2.6.9-gentoo-r1
        label = Single
        root = /dev/hda3
        append="S"
        read-only

but it boots to a login prompt as usual.
Replacing 'S' with 'single' doesn't work either.

Does anyone have single mode set up satisfactorily ?

-- 
========================,,============================================
SUPPORT     ___________//___,  Philip Webb : purslow@chass.utoronto.ca
ELECTRIC   /] [] [] [] [] []|  Centre for Urban & Community Studies
TRANSIT    `-O----------O---'  University of Toronto
-- 
gentoo-user@gentoo.org mailing list

Re: [gentoo-user] booting into single mode

[Mariusz Pękala]

[-- Attachment #1: Type: text/plain, Size: 1139 bytes --]

On 2005-08-31 09:25:48 -0400 (Wed, Aug), Philip Webb wrote:
> Is it still possible to boot into 'single' mode,
> ie directly into a no-login root system (for emergencies) ?
> 
> The kernel dox suggest this should work in Lilo
> 
>   image = /boot/kernel-2.6.9-gentoo-r1
>         label = Single
>         root = /dev/hda3
>         append="S"
>         read-only
> 
> but it boots to a login prompt as usual.
> Replacing 'S' with 'single' doesn't work either.
> 
> Does anyone have single mode set up satisfactorily ?

Not tested but found in 'man init', section 'BOOTFLAGS':

 -b, emergency
             Boot directly into a single user shell without running any
             other startup scripts.

..so, try with append="emergency"

The difference lies in that 'single' tells the init process to read and
execute entries in /etc/inittab, while 'emergency' tells to not do it.

You may also try with append="init=/bin/bash" or that nice rescue-shell
which name just slipped out of my memory.. /bin/sash maybe.

-- 
No virus found in this outgoing message.
Checked by 'grep -i virus $MESSAGE'
Trust me.

[-- Attachment #2: Type: application/pgp-signature, Size: 189 bytes --]

Re: [gentoo-user] booting into single mode

[Bert Buchholz]

On Wed 31.08 09:25, Philip Webb wrote:
> Is it still possible to boot into 'single' mode,
> ie directly into a no-login root system (for emergencies) ?

You can always do that by appending init=/bin/sh (for example) to the
kernel line when booting, so when lilo comes up, you append this text to
the kernel name.  You don't need to change lilo.conf unless you need
this very often, then it might be convenient to do so.  In lilo.conf you
would also just put

  append="init=/bin/sh"

to the kernel entry.

Bert
-- 
gentoo-user@gentoo.org mailing list

Re: [gentoo-user] booting into single mode

[Renat Golubchyk]

On Wed, 31 Aug 2005 09:25:48 -0400 Philip Webb <purslow@sympatico.ca>
wrote:
> Is it still possible to boot into 'single' mode,
> ie directly into a no-login root system (for emergencies) ?

Yes. Append "softlevel=single" to kernel boot parameters.


Cheers,
Renat


-- 
Probleme kann man niemals mit derselben Denkweise loesen,
durch die sie entstanden sind.
                                              (Einstein)
-- 
gentoo-user@gentoo.org mailing list

Re: [gentoo-user] booting into single mode

[Michele Noberasco]

[-- Attachment #1: Type: text/plain, Size: 462 bytes --]

On Wed, 31 Aug 2005 15:52:08 +0200
Mariusz P__kala <skoot@qi.pl> was read writing:

> You may also try with append="init=/bin/bash" or that nice
> rescue-shell which name just slipped out of my memory.. /bin/sash
> maybe.
Yup, this tells the kernel to run /bin/bash (or whatever you put in
there) instead of init...

-- 
"To hate man and worship god seems to be the sum of all the creeds."
       [Robert G. Ingersoll, "Some Mistakes of Moses" 1879]

[-- Attachment #2: Type: application/pgp-signature, Size: 189 bytes --]

Re: [gentoo-user] booting into single mode

[Philip Webb]

050831 Mariusz P?kala wrote:
> On 2005-08-31 09:25:48 -0400 (Wed, Aug), Philip Webb wrote:
>> Is it still possible to boot into 'single' mode,
>> ie directly into a no-login root system (for emergencies) ?
>> The kernel dox suggest this should work in Lilo
>> 
>>   image = /boot/kernel-2.6.9-gentoo-r1
>>         label = Single
>>         root = /dev/hda3
>>         append="S"
>>         read-only
>> 
>> but it boots to a login prompt as usual.
>> Replacing 'S' with 'single' doesn't work either.
>> Does anyone have single mode set up satisfactorily ?
> Not tested but found in 'man init', section 'BOOTFLAGS':
>   -b, emergency
>      Boot directly into a single user shell without running any
>      other startup scripts.
> so try with append="emergency"

Yes, that does make progress: the start-up process suspends,
while you have a chance to enter the root password "for maintenance";
after that, you have to exit with 'exit', when the process resumes
(or you can enter  ^d  & it skips maintenance mode).
"maintenance mode" seems to be equivalent to booting as root, but ...

> The difference lies in that 'single' tells the init process to read and
> execute entries in /etc/inittab, while 'emergency' tells to not do it.

... presumably it stops just before looking at  inittab .

> You may also try with append="init=/bin/bash"
> or that nice rescue-shell which name just slipped out of my memory.

Do you mean Busybox ?

> /bin/sash maybe.
 
That got superseded IIRC.

Thanx for the advice.  Does anyone else have further light to throw ?

-- 
========================,,============================================
SUPPORT     ___________//___,  Philip Webb : purslow@chass.utoronto.ca
ELECTRIC   /] [] [] [] [] []|  Centre for Urban & Community Studies
TRANSIT    `-O----------O---'  University of Toronto
-- 
gentoo-user@gentoo.org mailing list

Re: [gentoo-user] booting into single mode

[Philip Webb]

050831 Bert Buchholz wrote:
> On Wed 31.08 09:25, Philip Webb wrote:
>> Is it still possible to boot into 'single' mode,
>> ie directly into a no-login root system (for emergencies) ?
> You can always do that by appending init=/bin/sh to the kernel line

This gets the same result as 'append="emergency"',
ie it stops before inittab & asks for the root password;
afterwards, it exits into the regular start-up process
(thanx to the other user who also suggested this).

The other suggestion -- 'append="softlevel=single"' -- doesn't work
(no do 'S' or '1'): it says it can't find such a runlevel.

It looks as if this is a typically elegant Gentoo solution,
but unfortunately one which has not been documented properly anywhere.

Anyway, the conclusion is that for emergencies have an entry
which contains 'append="emergency"'; also, have a rescue diskette (smile).

-- 
========================,,============================================
SUPPORT     ___________//___,  Philip Webb : purslow@chass.utoronto.ca
ELECTRIC   /] [] [] [] [] []|  Centre for Urban & Community Studies
TRANSIT    `-O----------O---'  University of Toronto
-- 
gentoo-user@gentoo.org mailing list

Re: [gentoo-user] booting into single mode

[Ian Hastie]

On Wed, 31 Aug 2005 16:07:28 +0200
Renat Golubchyk <ragermany@gmx.net> wrote:

> Yes. Append "softlevel=single" to kernel boot parameters.

Do you know what the difference is, if any, between that and bootlevel?

-- 
Ian.

EOM
-- 
gentoo-user@gentoo.org mailing list