I'm using Ubuntu 9.10 as a KVM host. On this host there are 3 Debian 5 guests. When I start all the guests everything works fine, but after 1 to 3 days an exception (Kernel panic - not syncing: Fatal exception in interrupt) occurs.

After this error the KVM is dead, using all (100%) of his virtual CPU.

KVM Guest screenshot after crashing using VirtManager:


What is causing this fatal crash? Is it the virtual NIC ('vt82c598' in error message)?

The kernel crash errors can provide clues but the cause is often obscure. Process of elimination is required at this point.

Is it the same guest that fails or are all the guests failing? Is the failure happening around the same time or is it at a random time? Can the guest be started back up after failure or are there other issues? What do the guest and host logs show just before the failure?

Hi Chuck! Thank for your reply.

The crash happened 4 times on the same Guest. But this is the Guest that has currently the most (10 times more) network traffic. After a crash I have to force a shutdown. There are no problems when booting it again.

The 3 guests are made from the exact same installation (cloned). There is no specific time when it happens. Of 2 crashes I know that someone was uploading a lot of data to the guest.

I can't find any errors in the log files. I have checked all the systemlogs and the guest-specific log (/var/log/libvirt/qemu).

Some additional information:
Host kernel version: 2.6.31-20-server
KVM version: QEMU PC emulator version 0.11.0 (qemu-kvm-0.11.0), Copyright (c) 2003-2008 Fabrice Bellard
Network: Bridged

QEMU 12.3 is the most recent version. You should consider upgrading.

Since you suspect the network volume is the cause, are you using virtio network drivers? The default network emulators may not be able to keep up with the traffic volume.

I will download the source and try an update this weekend. The current installation is the newest ubuntu package.

Virtio is an option, but I don't think it's needed. The crash happens when the traffic increases, but it is not too much.

That's exactly why you need to use virtio network drivers. They improve network performance significantly over the standard network emulators.