Upgraded RAM but Kernel panic

To eliminate the memory, if you put the old memory back does the same message appear?

Can you compare the kernel compile options used under Gentoo with the options you used when compiling the kernel under Ubuntu. It could be a difference between these options (such as enabling APIC/ACPI or not, or a compiler bug).

I had the same problem as the reporter.

I found that the problem was not Ubuntu, but the fact that my board (NForce2) tried to use the two modules in dual channel mode. Memtest found no problems with the modules and the work flawlessly on another mainboard.

Knoppix and Windows hat the same problems with the "faulty" modules. Exchanging on of the modules with another one from another computer solved the problem.

I'd mark this bug as "invalid" as it has most likely nothing to do with Ubuntu.

I also have the same problem. I've got a laptop running kubuntu edgy on the generic kernel. Everything worked great when I had 1G of memory (512x2), but now I upgrade to 2G (1024x2) and I get a kernel panic when I boot.

However, Windows XP (my dual boot) has no problem with the memory, and (here's the clincher), the Kubuntu live install CD works with no problem. So, its something with the installed kernel, not with ubuntu per-se.

Works:
uname -a
Linux ubuntu 2.6.15-26-amd64-generic #1 SMP PREEMPT Thu Aug 3 02:52:35 UTC 2006 x86_64 GNU/Linux

Not Work: 2.5.17-10-generic

I'm not sure what the problem is...

Maybe something that the live CD probes for, but when it installs, it sticks the settings into the initrd? Its possible then that re-installing would solve the problem, but that's really a desperate move... I'd hate to have to rebuild so much of my system...

If windows and knoppix also had problems with your memory modules, then you had a different issue than this. In my case at least, its only ubuntu which has a problem, and only the installed version, not the livecd version...

I also have the same problem. I've got a laptop running kubuntu edgy on the generic kernel. Everything worked great when I had 1G of memory (512x2), but now I upgrade to 2G (1024x2) and I get a kernel panic when I boot.

However, Windows XP (my dual boot) has no problem with the memory, and (here's the clincher), the Kubuntu live install CD works with no problem. So, its something with the installed kernel, not with ubuntu per-se.

Works:
uname -a
Linux ubuntu 2.6.15-26-amd64-generic #1 SMP PREEMPT Thu Aug 3 02:52:35 UTC 2006 x86_64 GNU/Linux

Not Work: 2.5.17-10-generic

I'm not sure what the problem is...

Maybe something that the live CD probes for, but when it installs, it sticks the settings into the initrd? Its possible then that re-installing would solve the problem, but that's really a desperate move... I'd hate to have to rebuild so much of my system...

If windows and knoppix also had problems with your memory modules, then you had a different issue than this. In my case at least, its only ubuntu which has a problem, and only the installed version, not the livecd version...

I also have the same problem. I've got a laptop running kubuntu edgy on the generic kernel. Everything worked great when I had 1G of memory (512x2), but now I upgrade to 2G (1024x2) and I get a kernel panic when I boot.

However, Windows XP (my dual boot) has no problem with the memory, and (here's the clincher), the Kubuntu live install CD works with no problem. So, its something with the installed kernel, not with ubuntu per-se.

Works:
uname -a
Linux ubuntu 2.6.15-26-amd64-generic #1 SMP PREEMPT Thu Aug 3 02:52:35 UTC 2006 x86_64 GNU/Linux

Not Work: 2.5.17-10-generic

I'm not sure what the problem is...

Maybe something that the live CD probes for, but when it installs, it sticks the settings into the initrd? Its possible then that re-installing would solve the problem, but that's really a desperate move... I'd hate to have to rebuild so much of my system...

If windows and knoppix also had problems with your memory modules, then you had a different issue than this. In my case at least, its only ubuntu which has a problem, and only the installed version, not the livecd version...

What the hell... it put in my reply 3 times... [scratches head]...

After some more searching, I've discovered that appending mem=1000m to my boot parameters lets my machine boot up. Appearently, there's a bug associated with dma when memory gets over 1G.... I imagine that compiling my own kernel will solve the problem... I hope so at least.

Have you tried using the latest version of Ubuntu, 6.10, and does it have the same issues?

I've been using 6.10 (Edgy Eft) for a while now.

The generic kernels (including the most recent, 2.6.17-50-generic)
all have this issue.

Compiling my own from the source (the linux-source-2.6.17 (ver 2.6.17.1-50.50) package) is sufficient to eliminate the problem. I assume that is the same source that the generic is compiled from...

I'm not clear at this point if the problem was from the way something is compiled kernel, or from some module which my machine no longer attempts to load...