Dennis J. wrote: > Hi, > we are running Centos 5.2 on our servers for some time now and are really > happy with it. Now I'm investigating the best way to setup virtual machines > in order to streamline our infrastructure. The setup I'm aiming for is > Centos 5.2 guests on Centos 5.2 host. The physical systems are going to be > 2xquad core Xeons and the VMs are probably going to be 1 or 2 vCPUs with 1 > or 2 gb of ram for each guest. I plan to migrate a number of vmware > instances on such a setup so I'm wondering what I can expect > performance-wise when switching to either Xen or KVM. > > As far as I understand is Xen is the "official" supported solution with > Centos 5. I downloaded the KVM kernel module and some tools from a repo at > lfarkas.org (unfortunately the new virt-manager there cannot be installed > due to depency issues) to experiment with KVM which works so far but gives > me weird results. Doing a "hdparm -t" on the host system consistently gives > me a result of about 70MB/sec yet in a KVM guest I get results ranging from > 40MB/sec to 125MB/sec on each run. > > Also the Centos kernel does not support the virtio drivers needed for KVM > paravirtualization so I'm wondering how fast hardware assisted block-io > under KVM is compared to the performance of the paravirtualized Xen driver > and to vmware esx based guests. > > Are there any current performance benchmarks out there? I googled a bit but > only found some outdated and contested data on the web and virtualization > is a rather fast-moving field. may be worth waiting a little bit more, since: - rhel 5.3 released, so in a few weeks we'll have centos 5.3 and according rhel's annoncement it has some virtio_net support, - there'll be a new virt-manager and virtinst release in the near future (according to a last week's mail) which contains rhel-5 fixes. anyway imho xen is much more stable on rhel/centos-5 hosts then the current kvm line. kvm will be usable on kernel-2.6.29 and since rhel/centos-5 will be always 2.6.18 based we've towait for rhel/centos-6 which won't be in this year:-( or you can use other distro like fedora or ubuntu at least for host os. -- Levente "Si vis pacem para bellum!"