How to fix a bad Kernel Update? [SOLVED]

[ScottyK]

I did a fresh install of 10.10 x86, and once the system came up all updates came across fine.

Was able to update to KDE 4.5.5 with no problem.

The system wanted to update the kernel from 2.6.35-22 to 2.6.35.24, and that's where the problems started.

From the normal boot option, the system flashes a bit, then gives me a text logon prompt. Once I log in, I'm sitting at the command prompt.

When I try to start up KDE by typing "startx", I get a bunch off errors relating to the video card (Nvidia).

Things like.

Fatal - Module nvidia not found
nividia - failed to load the nividia kernel module
no drivers available

Fatal server error : no screens found.

xinit - no such file or directory (errno 2) unable to connect to x server
xinit - no such process (errno 3) server error

When I switch to booting the -22 kernel, everything boots fine.

Since it appears that my video drivers are borked, how can I fix it from the command line? I just checked and I have a connection to the internet to download whatever I need.

When I select the recovery mode option, The option "failsafeX" flashes a bit, then goes right back to the menu.
"Repair broken packages" returns no results.

I know I can boot into the -22 kernel and use the option "kdesudo kate /boot/grub/menu.lst", but if it's a simple fix to get the video up and running I'd like to stick with the -24 kernel.

Thanks!!

[oshunluvr]

Re: How to fix a bad Kernel Update?

This happens to me occasionally - sometimes un-installing the newer kernel, waiting a few days (for the nvidia installer to be updated) and then trying again is the easiest path.

Otherwise, disabling the nvidia driver - by uninstalling it and/or changing to nv or nouveux, install the new kernel, then re-install nvidia driver.

PITA I know, but this doesn't happen often anymore. It used to be what you had to do every time.

p.s. I assumed you're using the nvidia driver from the repos, not the d/l'd from nvidia...

[ScottyK]

Re: How to fix a bad Kernel Update?

removing the kernel is the option i'm going to run with.
Is the command to remove it -

Sudo apt-get remove linux-image-(kernel version)-generic?

Update - that command worked! I'll give it a couple of weeks before trying to update again.

[doctordruidphd]

Re: How to fix a bad Kernel Update? [SOLVED]

This is for future reference, since you have removed the offending kernel.

This depends on how you have installed your nvidia driver. If you used the "official" nvidia way -- by downloading the driver and installing it -- then you need to repeat that process for each kernel version update. -22 to -24 counts as a version update.

If you used the version that downloads through nvidia-current, then the script that installs it for the new kernel might have failed to run for some reason. You might try reconfiguring the kernel and see if it recompiles the driver.

sudo dpkg-reconfigure linux-image-2.6.35-24-generic

Now watch the process carefully -- you might get a warning message that you need to install the linux-headers in order for the driver to compile. In my case, the headers were installed along with the kernel, but not configured in time for the driver to compile. So I did a dpkg-reconfigure on the kernel after it had been set up, and all was well.

Also, should this kind of thing happen again, the old kernel is still there, and you should be able to boot with it, without removing the new one. If you are booting using the symlinks in / , you can manually change the links to initrd.img and vmlinuz to initrd.img.old and vmlinuz.old . If you are using the standard boot menu, you should find it listed among the boot options. You can change the default menu entry in /etc/default/grub to point to the entry you want to boot, and then update-grub. That's the easy way to change which kernel gets booted by default.

Hope this made some sense.

[ScottyK]

Re: How to fix a bad Kernel Update? [SOLVED]

Doc -

Thanks for the heads up. The plan is to give it a couple of weeks, then try the upgrade again.

I had a fresh install, then installed the nvidia driver through the System/Additional Drivers menu.

Then when the kernel went to update and reboot, I never got back to the GUI to install the drivers.

But this will come in handy if it borks again!

[ScottyK]

Re: How to fix a bad Kernel Update? [SOLVED]

Update (05 Mar 11)

Tonight I upgraded to the -27 kernel, and ran into the exact same problem as mentioned above.

From the command line I checked to see that I was running nvidia-current, and I was.

Then I ran the "dpkg-reconfigure" command as suggested by Doctordruidphd, and I saw two lines that were marked "fail".

Linux headers, and something else (vodx?)

Installed both those files by copying the line suggested in the error message.

Reran the dpkg-reconfigre command, rebooted, and now I'm sitting with the -27 kernel!

Good advice that came in handy months later!