Re: [CentOS-virt] performance differences between kvm/xen
If I understand that paper correctly, HVM+VT-d outperforms PV by quite a lot (if you have VT-d support on your system). Thanks for that link. Just to make my criticism of the initial claim more clear: I don't claim that HVM can never be faster than PV but that you need to understand when exactly this is the case. For example I'm not sure that x86_64 vs. x86 really enters into this but I can definitely see VT-d making an impact there. Regards, Dennis Even though this is Intel talking I'd still be very sceptical of getting those numbers since this is quite the opposite of what I've seen. Maybe the vt-d is getting good enough to actually accelerate IO operations but even so that would only happen on the latest hardware. I will say that Xen has a really long packet path though. Grant McWilliams ___ CentOS-virt mailing list CentOS-virt@centos.org http://lists.centos.org/mailman/listinfo/centos-virt
Re: [CentOS-virt] performance differences between kvm/xen
On 10/20/2010 08:12 AM, Grant McWilliams wrote: If I understand that paper correctly, HVM+VT-d outperforms PV by quite a lot (if you have VT-d support on your system). Thanks for that link. Just to make my criticism of the initial claim more clear: I don't claim that HVM can never be faster than PV but that you need to understand when exactly this is the case. For example I'm not sure that x86_64 vs. x86 really enters into this but I can definitely see VT-d making an impact there. Regards, Dennis Even though this is Intel talking I'd still be very sceptical of getting those numbers since this is quite the opposite of what I've seen. Maybe the vt-d is getting good enough to actually accelerate IO operations but even so that would only happen on the latest hardware. I will say that Xen has a really long packet path though. Being skeptical is the best approach in the absence of verifiable/falsifiable data. Today or tomorrow I'll get my hands on a new host system and although it is supposed to go into production immediately I will probably find some time to do some rudimentary benchmarking in that regard to see if this is worth investigating further. Right now I'm planning to use fio for block device measurements but don't know any decent (and uncomplicated) network i/o benchmarking tools. Any ideas what tools I could use to quickly get some useful data on this from the machine? Regards, Dennis ___ CentOS-virt mailing list CentOS-virt@centos.org http://lists.centos.org/mailman/listinfo/centos-virt
Re: [CentOS-virt] performance differences between kvm/xen
On 10/20/2010 12:35 PM, Dennis Jacobfeuerborn wrote: Being skeptical is the best approach in the absence of verifiable/falsifiable data. Today or tomorrow I'll get my hands on a new host system and although it is supposed to go into production immediately I will probably find some time to do some rudimentary benchmarking in that regard to see if this is worth investigating further. Right now I'm That sounds great. I've got a machine coming online in the next few days as well and will do some testing on there. Its got 2 of these : Intel(R) Xeon(R) CPU E5310 So not the newest/greatest, but should be fairly representative. planning to use fio for block device measurements but don't know any decent (and uncomplicated) network i/o benchmarking tools. Any ideas what tools I could use to quickly get some useful data on this from the machine? iozone and openssl speed tests are always a good thing to run as a 'warm up' to your app level testing. Since pgtest has been posted here already, I'd say that is definitely one thing to include so it creates a level of common-code-testing and comparison. mysql-bench is worth hitting as well. I have a personal interest in web app delivery, so a apache-bench hosted from an external machine hitting domU's / VM's ( but more than 1 instance, and hitting more than 1 VM / domU at the same time ) would be good to have as well. And yes, publish lots of machine details and also details on the code / platform / versions used. I will try to do the same ( but will limit my testing to whats already available in the distro ) thanks - KB ___ CentOS-virt mailing list CentOS-virt@centos.org http://lists.centos.org/mailman/listinfo/centos-virt
Re: [CentOS-virt] performance differences between kvm/xen
Ok so I'd like to help, since most folks have Intel Chipsets, I have a AMD 4p(16 core)/32gig memory opteron server that I'm running that we can get some numbers onbut it would be nice if we could run apples to apples...I have iozone loaded and can run that but would be nice to run using the same parametersis there any way we could list the types of test we would like to run and the actual command with options listed and then we would have some thing to compare at least level the playing field...KB, any thoughts, is this a good idea? On Wed, Oct 20, 2010 at 6:52 AM, Karanbir Singh mail-li...@karan.orgwrote: On 10/20/2010 12:35 PM, Dennis Jacobfeuerborn wrote: Being skeptical is the best approach in the absence of verifiable/falsifiable data. Today or tomorrow I'll get my hands on a new host system and although it is supposed to go into production immediately I will probably find some time to do some rudimentary benchmarking in that regard to see if this is worth investigating further. Right now I'm That sounds great. I've got a machine coming online in the next few days as well and will do some testing on there. Its got 2 of these : Intel(R) Xeon(R) CPU E5310 So not the newest/greatest, but should be fairly representative. planning to use fio for block device measurements but don't know any decent (and uncomplicated) network i/o benchmarking tools. Any ideas what tools I could use to quickly get some useful data on this from the machine? iozone and openssl speed tests are always a good thing to run as a 'warm up' to your app level testing. Since pgtest has been posted here already, I'd say that is definitely one thing to include so it creates a level of common-code-testing and comparison. mysql-bench is worth hitting as well. I have a personal interest in web app delivery, so a apache-bench hosted from an external machine hitting domU's / VM's ( but more than 1 instance, and hitting more than 1 VM / domU at the same time ) would be good to have as well. And yes, publish lots of machine details and also details on the code / platform / versions used. I will try to do the same ( but will limit my testing to whats already available in the distro ) thanks - KB ___ CentOS-virt mailing list CentOS-virt@centos.org http://lists.centos.org/mailman/listinfo/centos-virt ___ CentOS-virt mailing list CentOS-virt@centos.org http://lists.centos.org/mailman/listinfo/centos-virt
Re: [CentOS-virt] performance differences between kvm/xen
On Wed, Oct 20, 2010 at 6:24 AM, Tom Bishop bisho...@gmail.com wrote: Ok so I'd like to help, since most folks have Intel Chipsets, I have a AMD 4p(16 core)/32gig memory opteron server that I'm running that we can get some numbers onbut it would be nice if we could run apples to apples...I have iozone loaded and can run that but would be nice to run using the same parametersis there any way we could list the types of test we would like to run and the actual command with options listed and then we would have some thing to compare at least level the playing field...KB, any thoughts, is this a good idea? On Wed, Oct 20, 2010 at 6:52 AM, Karanbir Singh mail-li...@karan.orgwrote: On 10/20/2010 12:35 PM, Dennis Jacobfeuerborn wrote: Being skeptical is the best approach in the absence of verifiable/falsifiable data. Today or tomorrow I'll get my hands on a new host system and although it is supposed to go into production immediately I will probably find some time to do some rudimentary benchmarking in that regard to see if this is worth investigating further. Right now I'm That sounds great. I've got a machine coming online in the next few days as well and will do some testing on there. Its got 2 of these : Intel(R) Xeon(R) CPU E5310 So not the newest/greatest, but should be fairly representative. planning to use fio for block device measurements but don't know any decent (and uncomplicated) network i/o benchmarking tools. Any ideas what tools I could use to quickly get some useful data on this from the machine? iozone and openssl speed tests are always a good thing to run as a 'warm up' to your app level testing. Since pgtest has been posted here already, I'd say that is definitely one thing to include so it creates a level of common-code-testing and comparison. mysql-bench is worth hitting as well. I have a personal interest in web app delivery, so a apache-bench hosted from an external machine hitting domU's / VM's ( but more than 1 instance, and hitting more than 1 VM / domU at the same time ) would be good to have as well. And yes, publish lots of machine details and also details on the code / platform / versions used. I will try to do the same ( but will limit my testing to whats already available in the distro ) thanks - KB __ So what we're on the verge of doing here is creating a test set... I'd love to see a shell script that ran a bunch of tests, gathered data about the system and then created an archive that would then be uploaded to a website which created graphs. Dreaming maybe but it would be consistent. So what goes in our testset? Just a generic list, add to or take away form it.. - phoronix test suite ? - iozone - kernbench - dbench - bonnie++ - iperf - nbench The phoronix test suite has most tests in it in addition to many many others. Maybe a subset of those tests with the aim of testing Virtualization would be good? Grant McWilliams ___ CentOS-virt mailing list CentOS-virt@centos.org http://lists.centos.org/mailman/listinfo/centos-virt
