On Tue, Apr 16, 2013 at 09:49:20AM +0200, Martin Wawro wrote: > On 04/16/2013 07:49 AM, Stefan Hajnoczi wrote: > > Besides the kvm_stat, general performance data from the host is useful > > when dealing with high load averages. > > > > Do you have vmstat or sar data for periods of time when the machine was > > slow? > > > > Stefan > > We do have a rather exhaustive log on the guest. As for the host, we did > not find > anything suspicious except for the kvm_stat output. So we did not log > any more > than that. 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). > Here is the output of "vmstat 5 5" on the guest: > > procs -----------memory---------- ---swap-- -----io---- -system-- > ----cpu---- > r b swpd free buff cache si so bi bo in cs us sy > id wa > 84 0 19596 104404 60 21932616 0 0 232 110 9 2 7 > 2 90 1 > 80 0 19596 98100 60 21933920 0 0 106 119 854 912 79 > 21 0 0 > 89 0 19596 94216 60 21932764 0 0 106 223 864 886 79 > 21 0 0 > 87 0 19596 95848 60 21927612 0 0 82 47 856 906 79 > 21 0 0 > > Load average at that time: 75 (1:20 AM) 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. Stefan -- 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
