Comment 30 for bug 1007082

It's not really possible to determine too much more from these bad.page traces, we are getting some different kinds of random corruption, for example, different invalid page flags values and bad count values. So I think the best way forward is to install a debug kernel that I've built.

The debug kernel has VM debugging enabled which will slow the machine a little, but will add some more sanity checking and perhaps will give us some more information.

The kernel .debs are available here: http://kernel.ubuntu.com/~cking/lp-1007082/

We can take this one step further by trying to capture a kernel crash dump and I will inspect this crash image to try and see if this provides any further information. Crash dump images strip out a lot of unused data, but can be rather larger (several hundred MB) and there is of course the risk of sharing data in the kernel that you don't want to upload to launchpad, so the use of crashdump is up to you. Instructions on how to install, enable and trigger a crash dump image are here: https://wiki.ubuntu.com/Kernel/CrashdumpRecipe

You need to install linux-crashdump, reboot, check that crash kernel is loaded and then wait for the problem to manifest itself. Then trigger a crash and then I need to inspect the dump image saved in /var/crash - the notes for these steps are explained in the wiki page mentioned above.