Re: [libvirt] question about guest status

On Wed, Feb 15, 2012 at 02:44:18PM +0800, Wen Congyang wrote: > Hi all: > > If the guest runs on xen, we can know the guest OS paniced, and the guest status > is paniced. But if the guest runs on qemu/kvm, we need the same feature. And the > feature to know guest-is-panic is a very very good feature for enterprise. > > We have some ways to know that guest has paniced: > 1. watchdog timeouts > It is not a good way, because we can not say "the guest is paniced" in 100% accuracy > 2. use a PV driver(like the XEN) > The old RHELs do not have such driver... > It can not work for the second kernel... > 3. Adding a function for console-logging (in ring buffer or some) and check messages > given by guests. If we allow some filtering script or some, we can catch Linux's > panic messages. We can say the guest paniced if we catch such messages. We may be > able to catch other events by other script > > I prefer to 3 now. Does anyone have a better idea? I have discussed this with Anthony before and the thought was that QEMU/KVM should provide some kind of paravirtualized crash notification service to the guest. ie option 2. such a device would likely be quite simple and thus possible to backport to older kernels as needed