[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [Xen-devel] A Performance Comparison of Hypervisors

Nicholas Lee wrote:
Obviously not a very fair comparison [1]. I can't see how this was done well at all.

I wonder why you say this. I thought the benchmark was done very well. What we need is more benchmarking, not less. Unfortunately, VMware makes publishing benchmarks difficult as you have to get their approval.

This benchmark tells us something, the question is what does it tell us. Let's take a look at the benchmarks they choose. SPECcpu2000 and SPECjbb2005 are two favorite benchmarks of virtualization vendors. They are favorites because everyone does well under them :-) Both aren't sensitive to PTE update or context switch latency and don't involve IO very much. Even QEMU wouldn't look so bad against these :-)

I'm not familiar with Passmark, but it looks like it's mostly CPU bound. For all of these virtualization friendly workloads, Xen does pretty well compared to VMware. For some of the Passmark bits, Xen actually inches out VMware. Considering we're Open Source, they really have no excuse to ever be slower than we are :-)

The compile workload was, IMHO, the most serious of the benchmarks. VMware walloped us on that one. I suspect that's a some shadow paging overhead and perhaps some disk IO overhead.

The Netperf results are a tad silly. They choose Win2k3 for the guest OS. They installed a paravirtual network driver in their guest (vmxnet). However, since no PV network driver is available for Windows for Xen 3.0.3, they used emulated IO[1]. Of course performance is going to suck.

I would have rather seen the benchmarks done with a Linux guest using the PV drivers that are in the tree.

The only embarrassing part is that they weren't able to boot a Win2k3 guest with SMP support. I suspect we need either more QA for HVM or a better statement of supported guest confirmations.


Anthony Liguori

[1] The PV drivers that come in XenEnterprise are, AFAIK, only for XenEnterprise.

VMWare are a bit silly to release stuff like this, just lowers the whole game.

[1] http://www.vmware.com/vmtn/resources/711

Xen-devel mailing list

Xen-devel mailing list



Lists.xenproject.org is hosted with RackSpace, monitoring our
servers 24x7x365 and backed by RackSpace's Fanatical Support®.