Re: [User Question] Repeated severe performance problems on guest

On 04/19/2013 07:59 AM, Stefan Hajnoczi wrote: Hi Stefan, BTW does the host CPU support Intel Extended Page Tables or AMD Nested Page Tables? grep 'npt\|ept' /proc/cpuinfo (I think the kvm_stat is saying EPT/NPT are not in use) Host CPU has EPT. That is virt-manager.py, exactly doing

Re: [User Question] Repeated severe performance problems on guest

Hi Stefan, This morning we had to reboot the guest system again. pidstat logging was not enabled on the host (planned to do that later, hate myself for that). Again it looks like the schedulerinside the guest just does not want to schedule anymore (or takes coffee breaksinbetween), because tasks

Re: [User Question] Repeated severe performance problems on guest

On 04/18/2013 09:25 AM, Stefan Hajnoczi wrote: Hi Stefan, I see. That's a good reason to carefully monitor the host for things that could interfere with guest performance. Stefan Seems that today is a bad day for our server. We had to give him the boot (again). Also the results of the

Re: [User Question] Repeated severe performance problems on guest

On 04/18/2013 03:14 PM, Stefan Hajnoczi wrote: Dear Stefan, No answer but some more questions. Regarding the kvm_stat output, the exits are caused by 68,000 pagefaults/second (pf_fixed). Perhaps someone can explain what this means? The host has 8 cores, the guest has 7. Host pidstat

Re: [User Question] Repeated severe performance problems on guest

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

Re: [User Question] Repeated severe performance problems on guest

On 04/16/2013 07:49 AM, Stefan Hajnoczi wrote: Hi Stefan, 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

[User Question] Repeated severe performance problems on guest

Hi All, We are experiencing severe performance problems on a regular basis which require us to destroy and restart the guest OS. What happens is that the load average rises well above 50 and the guest OS becomes quite unresponsive, though no serious workload is running on the system. Even issuing

Re: [User question] Huge buffer size on KVM host

the (non-mounted) cdrom). cc += libvirt-list Is there a reason that cdroms don't get cache=none? -- Martin Wawro | Digital Medics GmbH Managing Director | Otto-Hahn-Str. 15, 44227

Re: [User question] Huge buffer size on KVM host

resides at around 1.8 GB after rebooting the VM (the only virtio device not having the cache=none option set is now the (non-mounted) cdrom). Best regards, -- Martin Wawro | Digital Medics GmbH

[User question] Huge buffer size on KVM host

.el5_5.25 (qemu 0.9.1, modules 2.6.18.194.17.1) libvirt 0.6.3 Guest: Ubuntu 10.04 (64-bit) running 2.6.32-27 virtio for storage and network Best regards, -- Martin Wawro | Digital Medics

Re: [User question] Huge buffer size on KVM host

= setting? We are using logical volumes and the cache is set to 'none'. With best regards, -- Martin Wawro | Digital Medics GmbH Managing Director | Otto-Hahn-Str. 15, 44227 Dortmund