Ubuntu 12.04 changed itself to xubuntu and stopped working

[Bret Busby]

On 31/07/2015, Petter Adsen <petter at synth.no> wrote:
> On Fri, 31 Jul 2015 03:08:21 +0800
> Bret Busby <bret.busby at gmail.com> wrote:
>
>> On 31/07/2015, Petter Adsen <petter at synth.no> wrote:
>> > On Fri, 31 Jul 2015 01:22:44 +0800
>> > Bret Busby <bret.busby at gmail.com> wrote:
>> >> So it appears that, even if the autologin line was there, I would not
>> >> be able to do anything to change it.
>> >
>> > See the answer that Nick gave you below for how to remount your root
>> > filesystem in rw mode. Then you will be able to alter files normally.
>> >
>>
>> I haven't sen any response from anyone named Nick, and I haven't sen
>> any information regarding how to remount the system in rw mode.
>
> Message-ID: <14edfcb7d25.11caba53a3424.6367672985120000358 at zoho.com>
>
> Sent 2015-07-30 18:28:51 +0200. Seems it was Ralf who sent it, with
> the interesting name "Nick Name", I didn't really read it until
> just now.

That message did not come through to my gmail account, that I had been
using so far in this.

The message does show in my other account, but the filters in my other
account, are such that, before being able to read messages, especially
from mailing lists, I need to go through my trap folders, and, the
filters on one of those trap folders, take about 15 minutes to
process.

Short summary:
>
> mount -o remount,rw / && mount -a
>
> After running that you should be able to purge any troublesome packages
> in the usual manner.
>
>> > When you attempt to boot normally and the screen goes blank, are you
>> > able to switch to a virtual console? Have you got the option of trying
>> > to access the system via the network to see if the rest of the system
>> > is alive and only the console or X is dead?
>> >
>>
>> Trying to access th system via a console, had not occured to me.
>>
>> I will try that and then log back into this installation.
>

Okay; I was able to go to a console (<CTRL><ALT><F1>) and log in, and
I purged the xubuntu and XFCE packages that were found.

I note that, in going to the console, both the laptop screen, and the
external monitor, displayed the console session.

I then rebooted, and got the Ubuntu splash screen, and then the system
again goes to the blank screen and displays nothing more, in the GUI
session.

In Ubuntu 14.04, when booting, I get the splash screen, then the
screen goes blank, and then, after a couple of seconds (or something
like that), the login screen is displayed.

It is that gap between the splash screen, and the login screen, where
the Ubuntu 12.04 installation boot process goes awry.

> Please do, as it will give a pretty clear indicator of whether it is
> just X/your display manager or if it goes deeper than that.
>
>> I have tried to ftp to another computer on this LAN, but was unable,
>> so I believe that, apart from accessing the Internet gateway to go
>> out, I am not able to have access between this computer and others
>> within the LAN.
>
> If you have network access you should be able to access local hosts,
> but they of course need to be running a service for you to contact. For
> very basic diagnostics, try to ping by IP address, just to see that the
> IP stack is up and connected.
>
>> > An idea of exactly what has hung would be very helpful to know where to
>> > go from here.
>> >
>>
>> How would I find what has hung?
>
> Well, my first suspects would be that either the X server or the video
> driver kernel module has died, or maybe lightdm. If the X server,
> there should be clues in /var/log/Xorg.0.log, if the kernel module
> then /var/log/dmesg and/or /var/log/kern.log would be a good place to
> start.
>
> Determining exactly what has happened would depend on what you find in
> those files. In Xorg.0.log errors will be marked (EE) and warnings
> (WW). Any error messages in dmesg are typically pretty obvious if you
> take a little time to look through them, paying special attention to
> anything that seems related to your GPU.
>
> If none of those seem to contain anything interesting, then look
> under /var/log/lightdm (if you are indeed running lightdm, I've got no
> idea what display manager 12.04 used by default). The files lightdm.log
> and x-0.log in that directory might be helpful.
>
> There are any number of things that could have gone wrong, but if the
> display is hung then these are the places where I would start.
>
> Petter
>
> --
> "I'm ionized"
> "Are you sure?"
> "I'm positive."
>

Local time here has reached about 0500, so I will resume in a few
hours or so, as my lucidity has reached its limit.

Thank you to everyone who has helped so far.

-- 
Bret Busby
Armadale
West Australia
..............

"So once you do know what the question actually is,
 you'll know what the answer means."
- Deep Thought,
 Chapter 28 of Book 1 of
 "The Hitchhiker's Guide to the Galaxy:
 A Trilogy In Four Parts",
 written by Douglas Adams,
 published by Pan Books, 1992

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