We support an enterprise application running on Windows Server 2008 R2. One of our customers has chosen to install to VMWare, and what I'm finding is that the VM's are relatively slow compared to hardware. Our product development team has advised that many VMs appear to run particularly slow on I/O benchmarks, which impact performance in production.
I've tried the AttoSoft I/O benchmark and find that for smaller I/O blocks (1-32K) the VM I'm looking at is 25x slower than hardware and for larger I/O blocks (1-8MB) it's 10x slower.
Is this a fair benchmark? If not, any suggestions for a fair test?