Hi,
I'm not sure anymore if I really tested your suggested disk virtio setup 
yesterday,
because today the vmu does not start when using the virtio setup.

During boot time, the volgroup00 can not be found. 
At the moment I'm still searching why this error occurs.

working: -drive file=/images/vmu01.raw,index=0,media=disk,boot=on
not working: -drive file=/images/vmu01.raw,index=0,media=disk,boot=on,if=virtio
not working: -drive file=/images/vmu01.raw,boot=on,if=virtio

-----Ursprüngliche Nachricht-----
Von: Hauke Hoffmann [mailto:kont...@hauke-hoffmann.net] 
Gesendet: Montag, 6. April 2009 14:13
An: kvm@vger.kernel.org
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


>
>
>
>
>
> ________________________________
>
> 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.br...@alcatel-lucent.de
>
>
>
> 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 majord...@vger.kernel.org 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: off...@hauke-hoffmann.net
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 majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Reply via email to