I have been able to reproduce the bug and found out what goes wrong. After creating 79 VM's with all 2 vbd (root disk and swap) and one vif i ran into the problem again.
One error caught my attention (and is only mentioned once!): [ 628.040958] No available IRQ to bind to: increase NR_DYNIRQS. After some searching i found: * https://bugzilla.redhat.com/show_bug.cgi?id=442736 * http://www.nabble.com/Unable-to-start-more-than-103-VMs-td11420853.html I downloaded the source of "linux-image-2.6.24-23-xen" and modified "debian/binary-custom.d/xen/patchset/001-xen-base.patch" on line 87148 Here you should change NR_DYNIRQS from 256 to 1024. When you have a VM with 3 "devices" (in my case 2x vbd, 1x vif) you reserve 3 Dynamic IRQ's per domU. 79 * 3 = 237 IRQ's The default limit of 256 is reached since the dom0 also reserves some IRQ's. You can find out how many IRQ's you are using with: grep Dynamic-irq /proc/interrupts |wc -l I have now been able to address over 256 IRQ's and start 90 VM's without any troubles. I think Ubuntu should raise the limit from 256 to 512 or 1024 OR make it a option wich can be passed to the kernel on boot (like suggested in the RedHat bugreport) -- No network connectivity for new domU's (No available IRQ to bind to: increase NR_DYNIRQS) https://bugs.launchpad.net/bugs/341846 You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
