With KVM guest, is that performance measured using virtio? If not, maybe you could try that.
On 05/12/2010 09:30 AM, David Peall wrote: > Hi > > I've been using KVM for a bunch VM's on hardy and now Lucid and with > CPU and memory performing quite well its been no problem. I'm now > looking at our ageing DB server and wanting to put it in a VM but the > disk performance is dismal or am I doing it wrong? > I'm quite comfortable if I loose 25% or even 33% through > virtualization as the benefits are worth it. > > Here are the numbers I have so far (using dbench, ubuntu lucid and > ext4): > > Bare metal using a slice for the host OS: > Throughput 2586.65 MB/sec 10 clients 10 procs > max_latency=18.029 ms > Throughput 3631.62 MB/sec 50 clients 50 procs > max_latency=239.773 ms > Throughput 3635.12 MB/sec 100 clients 100 procs > max_latency=458.094 ms > > Guest KVM machine using a block device > Throughput 1130.52 MB/sec 10 clients 10 procs > max_latency=262.047 ms > Throughput 513.972 MB/sec 50 clients 50 procs > max_latency=6561.761 ms > Throughput 465.593 MB/sec 100 clients 100 procs > max_latency=2520.585 ms > > I tried VMware just as a comparison using a vmdk file (not even a block > device): > Throughput 1482.44 MB/sec 10 clients 10 procs > max_latency=53.682 ms > Throughput 2049.45 MB/sec 50 clients 50 procs > max_latency=492.187 ms > Throughput 2098.71 MB/sec 100 clients 100 procs > max_latency=681.216 ms > > Using LVM was worse and Qcow2 was even worse as expected. > > Thats a big pill to swallow for KVM. > > Any ideas what is the best way to get disk performance using KVM. > > Thanks > -- Imre Gergely Yahoo!: gergelyimre | ICQ#: 101510959 MSN: gergely_imre | GoogleTalk: gergelyimre gpg --keyserver subkeys.pgp.net --recv-keys 0x34525305 -- ubuntu-server mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-server More info: https://wiki.ubuntu.com/ServerTeam
