This is a multi-part message in MIME format. ------=_NextPartTM-000-d054cc3c-0c15-4f69-9a41-aef4c6c9caf1 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable Hello,=0A= =0A= a few weeks ago I started investigating ovirt as an alterantive to a well= =0A= known commercial virtualization center. Up to now I got great support=0A= through this mailing list. Thanks for that. With all the technical things= =0A= sorted out I'm getting slowly to the performance related stuff.=0A= =0A= Lets start with a small explanation to the test landscape. I have two=0A= hypervisor machines (Intel Nehalem generation) that are attached to=0A= a NFS server via infiniband IPoIB connected mode (MTU 33000). They =0A= run Fedora 19 (kernel 3.11) and through newest repositories qemu =0A= version 1.6.0 - 7.fc19.=0A= =0A= To get an idea about the overhead of the VM disk layer I run a not very=0A= scientific direct I/O read test on the hypervisor onto a image file that=0A= resides on the NFS share. Access pattern is random, I use one thread,=0A= blocksize is 1K and the file (image that belongs to a VM) is fully cached = =0A= on the NFS server. So no disk activity is going on in the NFS server but = =0A= block reads are always sent over the network. The numbers read 13 =0A= MB/sec or 13000 IOs/sec. Just take that as a very synthetic reference =0A= value for the latency of the NFS layer.=0A= =0A= Now I relocate my test into one of the running VMs. Again a Fedora 19=0A= that uses virtio-scsi based disk images on the NFS. The IOs drop to =0A= 9.5MB/sek or 9500 IOs/sec. I understand that virtualization costs =0A= performance so I'm still statisfied.=0A= =0A= With Windows 7 VM and the virtio-0.1-65 driver I get a real bad experience.= =0A= Only 2MB/sek or 2000 IOs/sec left. That is not what one would expect. =0A= =0A= I read through articles/papers about the different approaches in the last= =0A= years to increase VM IO performance: virtio-data-plane, virto-blk, ...=0A= But I'm not yet searching to increase the overall performance I'm just=0A= trying to get biggest mistakes sorted out. With the same devices and =0A= on the same platform I expect the performance of both VMs to be in a =0A= similar range and not a difference by a factor of 4-5.=0A= =0A= Any ideas?=0A= =0A= Markus= ------=_NextPartTM-000-d054cc3c-0c15-4f69-9a41-aef4c6c9caf1 Content-Type: text/plain; name="InterScan_Disclaimer.txt" Content-Transfer-Encoding: 7bit Content-Disposition: attachment; filename="InterScan_Disclaimer.txt" **************************************************************************** Diese E-Mail enthält vertrauliche und/oder rechtlich geschützte Informationen. Wenn Sie nicht der richtige Adressat sind oder diese E-Mail irrtümlich erhalten haben, informieren Sie bitte sofort den Absender und vernichten Sie diese Mail. Das unerlaubte Kopieren sowie die unbefugte Weitergabe dieser Mail ist nicht gestattet. Über das Internet versandte E-Mails können unter fremden Namen erstellt oder manipuliert werden. Deshalb ist diese als E-Mail verschickte Nachricht keine rechtsverbindliche Willenserklärung. Collogia Unternehmensberatung AG Ubierring 11 D-50678 Köln Vorstand: Kadir Akin Dr. Michael Höhnerbach Vorsitzender des Aufsichtsrates: Hans Kristian Langva Registergericht: Amtsgericht Köln Registernummer: HRB 52 497 This e-mail may contain confidential and/or privileged information. If you are not the intended recipient (or have received this e-mail in error) please notify the sender immediately and destroy this e-mail. Any unauthorized copying, disclosure or distribution of the material in this e-mail is strictly forbidden. e-mails sent over the internet may have been written under a wrong name or been manipulated. That is why this message sent as an e-mail is not a legally binding declaration of intention. Collogia Unternehmensberatung AG Ubierring 11 D-50678 Köln executive board: Kadir Akin Dr. Michael Höhnerbach President of the supervisory board: Hans Kristian Langva Registry office: district court Cologne Register number: HRB 52 497 **************************************************************************** ------=_NextPartTM-000-d054cc3c-0c15-4f69-9a41-aef4c6c9caf1--