Hi, yesterday I've had a problem on a server hosting 5 KVM domains managed with libvirt. The first symptoms were connectivity problems, and it appeared there were 2 domains showing problems: 1) a domain had a disk image configured as IDE and not virtio, and had these logs: http://pastie.org/8881997 2) a second domain was overloaded and out of memory, and I suspect it was swapping heavily.
The total memory assigned to the domains was less than half the memory on the host. The host CPU is a quad core. The host CPU usage and memory usage was low, but its load was 15+. Operations on the host were slow. For example copying a qcow image paused seconds and even tens of seconds a took a long time to complete. When the copy paused, I looked at the vmstat output, and the bo was 0! I'm trying to understand what happened to prevent it from happening again. Anyone having suggestions? I'm using qemu-1.7.0 and libvirt 1.2.1, but on an old kernel 2.6.32. Thanks Raph
