If you are suffering a mouth breathing moment like I did today, happen to be using Ubuntu Edgy and found that after an update, that your GUI has suddenly left the building – don’t panic. Just try this.

First off, boot from a live CD on the problem PC. Now open up a terminal window and type the following:

sudo fdisk -l

Now understand, that is a lower case ‘L’, not an upper case ‘I’ on the end there. Depending on whether you are running with SATA drives or IDE, you’ll end up with something that looks something like this:

Disk /dev/sda: 300.0 GB, 300069052416 bytes
255 heads, 63 sectors/track, 36481 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

Device Boot      Start         End      Blocks   Id  System
/dev/sda1   *           1       36104   290005348+  83  Linux
/dev/sda2           36105       36481     3028252+   5  Extended
/dev/sda5           36105       36481     3028221   82  Linux swap / Solaris

Confused yet? Not to worry. All you need to do is look for the line that says ‘Linux’ and the number blocks that are larger than the rest. If you are dual-booting, then you would look for the large number again, but remember to watch for the line ‘Linux’ under the system label. Make a note of which device it is. In my case, it’s going to be /dev/sda1 .

Now from the same terminal window, let’s get this drive mounted so we can save this data in case recovery goes south, shall we? The next thing to pound out into the terminal window is the following:

mkdir /backup

This creates a directory that will soon be pointing to your actual hard drive, that we will be recovering. Now type this:

mount /dev/device-name-seen-above-here /backup

So in this instance, I would be mounting /dev/sda1 . You on the other hand, might be mounting something else, depending on the output of your fdisk output.

After hitting enter on that last line, you should see a new folder appearing on the desktop on the booted live CD. Click into it and see if you are able to view its contents. You will want to mainly navigate to /home/your-user-name .

Now make sure to goto view, then the show hidden files. This will enable you to save your email settings along with your Firefox settings as well. Firefox data saving is rather easy, just look for .firefox and save it to an external hard drive, which you should now plug into the PC itself. It will after a few seconds, show up on your desktop as well if it is formated in a Linux friendly file system. NTFS may show up, but it is hardly Linux friendly.

As for Evolution, this can be a little trickier. You will need to locate the following folders:

.evolution

.gconf/apps/evolution

.gnome2_private/Evolution

Each folder needs to be backed up and notes taken as to their perspective locations for being placed back if needed. Grab whatever else is critical from the Home folder and let’s see about getting that UI back up and running. Reboot your PC and remove the CD.

Immediately after the BIOS screen comes up, you will just for a second, see where it says in the upper left to ‘press Esc’ for more options. This is your hidden GRUB (boot) menu, press Esc and then select the third line down. This will allow you to boot into the kernel you were using previously.

Once you manage to get back into your Ubuntu PC, you will be feeling a lot better. You have your important data backed up and of course, you can now take steps to put this other kernel out to pasture. First, open up a terminal window and type the following to figure out which kernel you are running now which is working for you.

uname -r

Your output should look something like this:

2.6.17-11-generic

If this is the case, then it stands to reason that 2.6.17-12 is the problem kernel. Knowing this, goto System, Administration and choose Synaptic. Do a search for linux-image.

Remembering that we like -11 and want to kill off the -12 kernel (linux-image), you would look for two entries for this problem kernel.

-linux-image-2.6.17-12-386

and

-linux-image-2.6.17-12-generic

**Remember, the kernel numbers used are just examples and not to be taken as the exact ones to be removed. Knowing that the higher numbered entries are the two you are looking for however, go ahead and remove them both once you are sure, then reboot. If all went well, you have just rolled your kernel back to where it was before Ubuntu hosed your system! 😉

[tags]Linux,PC backup[/tags]