[GTALUG] Ubuntu update gone bad

[Kevin Cozens]

On 15-08-09 11:11 AM, D. Hugh Redelmeier wrote:
> I took an Acer Revo out of service as an HTPC.  It was dual boot Win 7 and
> Ubuntu 12.04 LTS.
[snip]
> I applied all Ubuntu 12.04 updates.  Fine.  Not even stupid.
>
> It offered me Ubuntu 14.04 LTS.  I said to go ahead.  I almost never do
> version upgrades, out of fear, but I didn't have much to lose.  And
> everyone always says Ubuntu version upgrades are smooth as silk.

You jumped over 3 other releases in between. One of which would have been 
another LTS release. I have done upgrades in Ubuntu when I used to run it 
and I usually had no problem. In my case I would do a series of upgrades 
when I only two or three releases behind the current one. If I am too far 
behind then I would go the route of a fresh install.

You are jumping up by four releases and you can find some programs were 
replaced by other programs which can complicate the upgrade process in some 
situations.

> Negative observation one: version upgrades take more real time than
> re-installations.

Yes, they often can.

> Negative observation two: I thought that the slow upgrade process could
> happen while I was asleep.

I prefer to do the updates during the day so I can keep an eye on it. There 
are extra questions that can be asked of you during an install that would 
bring the process to a halt until an answer is provided.

> Negative observation three:  It all appeared to work.  The updater
> disappeared from the screen (a little odd).  top(1) showed no remnant.
> So I rebooted.  Now I have the prompt:
> 	grub rescue>
> which means I have nothing, not even Win7.  I don't think that I can type
> anything useful into that prompt.

This could be one of a few issues. It could be a failed update to the grub 
bootloader, it could be the Windows update changed the boot partitions or 
removed the grub bootloader, or possibly a UEFI related boot issue.

If (or, rather when) Windows update messed with the bootloader it usually 
makes it so the system boots straight to Windows. Seeing a grub prompt means 
that is not the case here.

You can go in to the BIOS of your computer and disabled UEFI boot. I ran in 
to an issue with it on one of my systems. If that isn't the case you may be 
able to issue some commands at the grub prompt to get the system to boot.

I don't know if things are the same with grub 2 but in grub 1 you would use 
four commands. "root", "linux", "initrd", and finally "boot" to get the 
system up.

For example:
root (hd0,1)
linux /boot/vmlinuz-<insert-kernel-version-here>
initrd /boot/initrd.img-<insert-kernel-version-here>
boot

The root line would point to the drive and partition containing the linux 
kernel and initrd files (what you know often know as /boot when the system 
is running).

The linux and initrd lines can take command line completion so you can hit 
the tab key to see which kernel and/or initrd files are available. The last 
word "boot" takes no arguments. It uses the information from the first three 
commands and attempts to boot your system.

-- 
Cheers!

Kevin.

http://www.ve3syb.ca/           |"Nerds make the shiny things that distract
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