-----Ursprüngliche Nachricht----- Von: Hauke Hoffmann [mailto:kontakt@xxxxxxxxxxxxxxxxxx] Gesendet: Montag, 6. April 2009 14:13 An: kvm@xxxxxxxxxxxxxxx Cc: BRAUN, Stefanie Betreff: Re: KVM performance On Friday 03 April 2009 13:32:50 you wrote: > Hallo, > > as I want to switch from XEN to KVM I've made some performance tests > to see if KVM is as peformant as XEN. But tests with a VMU that > receives a streamed video, adds a small logo to the video and streams > it to a client have shown that XEN performs much betten than KVM. > In XEN the vlc (videolan client used to receive, process and send the > video) process > within the vmu has a cpuload of 33,8 % whereas in KVM the vlc process > has a cpuload of 99.9 %. > I'am not sure why, does anybody now some settings to improve the KVM > performance? > > Thank you. > Regards, Stefanie. > > > Used hardware and settings: > In the tests I've used the same host hardware for XEN and KVM: > - Dual Core AMD 2.2 GHz, 8 GB RAM > - Tested OSes for KVM Host: Fedora 10, 2.6.27.5-117.fc10.x86_64 with > kvm version 10.fc10 version 74 > also tested in january: compiled kernel > with > kvm-83 > > - KVM Guest settings: OS: Fedora 9 2.6.25-14.fc9.x86_64 (i386 also > tested) > RAM: 256 MB (same for XEN vmu) > CPU: 1 Core with 2,2 GHz (same for XEN vmu) > tested nic models: rtl8139, e1000, virtio > > Tested Scenario: VMU receives a streamed video , adds a logo > (watermark) to the video stream and then streams it to a client > > Results: > > XEN: > Host cpu load (virt-manager): 23% > VMU cpu load (virt-manager): 18 % > VLC process within VMU (top): 33,8% > > KVM: > no virt-manager cpu load as I started the vmu with the kvm command > Host cpu load : 52% > qemu-kvm process (top) 77-100% > VLC process within vmu (top): 80 - 99,9% > > KVM command to start vmu > /usr/bin/qemu-kvm -boot c -hda /images/vmu01.raw -m 256 -net > nic,vlan=0,macaddr=aa:bb:cc:dd:ee:10,model=virtio -net > tap,ifname=tap0,vlan=0,script=/etc/kvm/qemu-ifup,downscript=/etc/kvm/q > em u-ifdown -vnc 127.0.0.1:1 -k de --daemonize Hi Stefanie, does vlc perform operations on disc (eg caching, logging, ...)? When it cache you can use virtio also for the disk. Just change -hda /images/vmu01.raw to -drive file=/images/vmu01.raw,if=virtio,boot=on Regards Hauke Hi Hauke, Thanks for your replay. The vlc does not perform excessive operations on disc. Even so I've added disk virtio to the vmu setup. But the qemu-kvm process in the host and the vlc process within the vmu still consume up to 100%. Regards, Stefanie > > > > > > ________________________________ > > Alcatel-Lucent Deutschland AG > Bell Labs Germany > Service Infrastructure, ZFZ-SI > Stefanie Braun > Phone: +49.711.821-34865 > Fax: +49.711.821-32453 > > Postal address: > Alcatel-Lucent Deutschland AG > Lorenzstrasse 10 > D-70435 STUTTGART > > Mail: stefanie.braun@xxxxxxxxxxxxxxxxx > > > > Alcatel-Lucent Deutschland AG > Sitz der Gesellschaft: Stuttgart - Amtsgericht Stuttgart HRB 4026 > Vorsitzender des Aufsichtsrats: Michael Oppenhoff Vorstand: Alf Henryk > Wulf (Vors.), Dr. Rainer Fechner > > ________________________________ > -- > 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 -- hauke hoffmann service and electronic systems Moristeig 60, D-23556 Lübeck Telefon: +49 (0) 451 8896462 Fax: +49 (0) 451 8896461 Mobil: +49 (0) 170 7580491 E-Mail: office@xxxxxxxxxxxxxxxxxx PGP public key: www.hauke-hoffmann.net/static/pgp/kontakt.asc -- 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
