Hi Stefan, > The host is interesting too if you suspect KVM is involved in the > performance issue (rather than it being purely an application issue > inside the guest). For example, pidstat (from the sysstat package) on > the host can tell you the guest mode CPU utilization percentage. That's > useful for double-checking that the guest is indeed using up a lot of > CPU time (the guest data you posted suggests it is). I added it to the host logging to have more information next time something goes haywire. > > What does top or ps say about the 79% userspace CPU utilization? > Perhaps this is unrelated to KVM and simply a buggy application going > nuts. > In this case, it was postgres (we have a couple of instances running on the guest). But it can also be another daemon process that usually behaves very well, so no real culprit to pinpoint it to. We have the same setup (including OS versions and binary versions) in other locations (on "physical machines") running for years without any problems, so I doubt that this is an application issue. Another hint that it is not an application issue is the fact, that when we shutdown the processes that generate the load, the load average goes down for a couple of seconds and then again rises to sky-high values with another process consuming the load (until nothing is left running on the machine except for syslogd :-) ). Best regards, Martin -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
