Re: [tlug] Not understanding how updated kernels work

[Edward Middleton <edward@example.com>]

Dave M G wrote:
> The other day, Ubuntu gave me a notice that there were some updates I
> needed to install. I went ahead and updated everything, and then at the
> end it said I needed to reboot in order for the updates to take effect.
>   
> It wasn't a complete surprise, mind you. My video card is very new, and
> I had to get drivers direct from Nvidia in order to get X working at all.
>   

This is the point everyone was trying to make.  If you get drivers that
are not directly from Ubuntu they will likely break when you upgrade.
You will have to manually check each update, not just update
everything.   Is you card really not supported by the standard Ubuntu
nvidia packages?  If this is the case you should file a bug[1].

> I tried running the Nvidia driver install utility again, but it
> complained it could not find nvidia.ko in the right place or something,
> and wouldn't work.
>   

Drivers are only expected to work with the kernel they are compiled
against, and as such, they are in a versioned directories.  Look in
/lib/modules and you will see the directories.  If you upgrade the
kernel you have to upgraded (i.e. install) all the drivers for that
kernel version (they are a set even if they are packaged separately). 
The nvidia drivers you got directly from nvidia are probably only for
the older kernel.  You will either have to

1. use the Ubuntu nvidia drivers package
2. wait from the "direct from nvidia" drivers to be updated
3. use the older kernel.

> The basic short story is that the kernel was upgraded from 2.16.20 to
> 2.16.21, and the new kernel doesn't like my graphics card or something.
>   

As pointed out you probably don't have drivers for the newer kernel version.

Edward

1. http://www.ubuntu.com/support/bugs