Re: Incorrect password Debian 10.8 after installation

From	David Wright <deblis@lionunicorn.co.uk>
Newsgroups	linux.debian.user
Subject	Re: Incorrect password Debian 10.8 after installation
Date	2021-02-09 16:40 +0100
Message-ID	<BGDho-2WW-11@gated-at.bofh.it> (permalink)
References	<BG4MF-5QX-13@gated-at.bofh.it> <BGap4-Ud-15@gated-at.bofh.it> <BGlXc-dm-23@gated-at.bofh.it> <BGnYZ-1te-1@gated-at.bofh.it> <BGqWR-3nn-11@gated-at.bofh.it>
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On Mon 08 Feb 2021 at 18:26:22 (-0800), David Christensen wrote:
> On 2021-02-08 15:15, David Wright wrote:
> > On Mon 08 Feb 2021 at 13:02:21 (-0800), David Christensen wrote:
> > > On 2021-02-08 00:40, Marco Möller wrote:
> > > 
> > > > You could bypass any password request during boot to the console
> > > > and then fix it by setting the desired password newly. The boot
> > > > parameter for bypassing all password request an right away
> > > > becoming logged in as user root is:
> > > >       init=/sbin/sulogin --force
> > > 
> > > That is interesting.  But, how does the reader *use* that information[?] ...
> 
> > > Booting a Stretch system, I see a menu:
> > > 
> > >      GNU GRUB  version 2.02~beta3-5+deb9u2
> > > 
> > >      *Debian GNU/Linux
> > >       Advanced options for Debian GNU/Linux
> 
> > > If I press 'e', it (GRUB?) appears to bring up an editor window that
> > > contains a bunch of content that looks relevant.  The last few lines
> > > are:
> > > 
> > >      ....
> > >      echo        'Loading Linux 4.9.0-9-amd64 ...'
> > >      linux       /vmlinuz-4.9.0-9-amd64 root=UUID=... ro noresume
> > >      echo        'Loading initial ramdisk ...'
> > >      initrd      /initrd.img-4.9.0-9-amd64
> > 
> > … and that's the menu version of the commands outlined in 5.3.2.
> 
> > Yes, [add the suggested parameters]to the linux line: it's a kernel parameter.
> 
> > > Where is this documented?
> > 
> > I always go to
> > 
> > https://www.kernel.org/doc/html/v4.15/admin-guide/kernel-parameters.html
> > 
> > (where v4.15 could be different).
> > 
> >      init=           [KNL]
> >        Format: <full_path>
> >        Run specified binary instead of /sbin/init as init process.
> > 
> > where KNL confirms it's a Kernel parameter. The introduction shows:
> > 
> >      BUGS=   Relates to possible processor bugs on the said processor.
> >      KNL     Is a kernel start-up parameter.
> >      BOOT    Is a boot loader parameter.
> 
> Thank you for the information.  :-)
> But, it still does not answer the question -- how does the reader
> *use* the suggested "boot parameter"?
> 
> My WAG (untested):
> 
> 1.  Power up the computer.
> 2.  The GRUB menu should be displayed:
> 
>         *Debian GNU/Linux
>          Advanced options for Debian GNU/Linux
> 
> 3.  Press the down arrow key to highlight "Advanced options for Debian
> GNU/Linux".  Press <Enter> to select it.

If you're heading for sulogin, I'm not sure it matters which line you
pick, as it means s(ingle)u(se)rlogin.

> 4.  A second GRUB menu should be displayed (the OP should have a newer
> kernel):

Yes, you warned us you're using stretch.

>         *Debian GNU/Linux, with Linux 4.9.0-9-amd64
>          Debian GNU/Linux, with Linux 4.9.0-9-amd64 (recovery mode)
> 
> 5.  Press the down arrow key to select the "... (recovery mode)" boot
> entry.  Press 'e' to edit it.
> 
> 6.  The GRUB editor should start and display the contents of the
> selected boot entry.  Look for the line that begins with 'linux'.  Use
> the cursor keys to move the insertion point to the end of that line
> and add the following kernel boot parameters:
> 
>         init=/sbin/sulogin --force
> 
> 7.  "Press Ctrl+x or F10 to boot".
> 
> Is the above correct?

Yes. AIUI --force deals with the case where there is no root
password/the root account is locked. But my understanding might be
faulty as I always set a root password in decades-old tradition.
As a result, I'm always prompted for a password. To reset *that*,
I'd either boot up my other system on the disk, or boot from a
stick/CD.

> Questions:
> 
> 1.  How do I make a copy of a boot entry?  (So that I can edit the
> copy and keep the original.)
> 
> 2.  How do I insert a tab character with the GRUB editor?  (Pressing
> <Tab> causes the editor to attempt command completion.)

I think Greg's guess was good. You don't need tabs or any other cosmetics.

> 3.  Will changes made to a boot entry with the GRUB editor persist for
> subsequent boots?

No. Just write down what you change, so that you can fold it in to your
Grub configuration later if it worked.

Cheers,
David.

Thread

Incorrect password Debian 10.8 after installation John Berden <john.berden4@gmail.com> - 2021-02-08 03:50 +0100
  Re: Incorrect password Debian 10.8 after installation Andrei POPESCU <andreimpopescu@gmail.com> - 2021-02-08 09:30 +0100
  Re: Incorrect password Debian 10.8 after installation Marco Möller <talby@debianlists.mobilxpress.net> - 2021-02-08 09:50 +0100
    Re: Incorrect password Debian 10.8 after installation Keith Bainbridge <ke1thrboz@gmx.com> - 2021-02-08 10:50 +0100
    Re: Incorrect password Debian 10.8 after installation David Christensen <dpchrist@holgerdanske.com> - 2021-02-08 22:10 +0100
      Re: Incorrect password Debian 10.8 after installation David Wright <deblis@lionunicorn.co.uk> - 2021-02-09 00:20 +0100
        Re: Incorrect password Debian 10.8 after installation David Christensen <dpchrist@holgerdanske.com> - 2021-02-09 03:30 +0100
          Re: Incorrect password Debian 10.8 after installation Anssi Saari <as@sci.fi> - 2021-02-09 08:30 +0100
            Re: Incorrect password Debian 10.8 after installation David Christensen <dpchrist@holgerdanske.com> - 2021-02-09 08:40 +0100
              Re: Incorrect password Debian 10.8 after installation <tomas@tuxteam.de> - 2021-02-09 10:00 +0100
                Re: Incorrect password Debian 10.8 after installation Anssi Saari <as@sci.fi> - 2021-02-09 17:30 +0100
                Re: Incorrect password Debian 10.8 after installation David Christensen <dpchrist@holgerdanske.com> - 2021-02-09 23:00 +0100
                Re: Incorrect password Debian 10.8 after installation Erwan David <erwan@rail.eu.org> - 2021-02-10 07:50 +0100
                Re: Incorrect password Debian 10.8 after installation Stefan Monnier <monnier@iro.umontreal.ca> - 2021-02-09 23:30 +0100
                Re: Incorrect password Debian 10.8 after installation Greg Wooledge <wooledg@eeg.ccf.org> - 2021-02-10 13:40 +0100
          Re: Incorrect password Debian 10.8 after installation Greg Wooledge <wooledg@eeg.ccf.org> - 2021-02-09 13:50 +0100
            Re: Incorrect password Debian 10.8 after installation David Christensen <dpchrist@holgerdanske.com> - 2021-02-09 23:00 +0100
              Re: Incorrect password Debian 10.8 after installation David <bouncingcats@gmail.com> - 2021-02-09 23:20 +0100
          Re: Incorrect password Debian 10.8 after installation David Wright <deblis@lionunicorn.co.uk> - 2021-02-09 16:40 +0100
            Re: Incorrect password Debian 10.8 after installation David Christensen <dpchrist@holgerdanske.com> - 2021-02-10 00:00 +0100

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