Using the VMware I/O Analyzer v1.5: A Guide to Testing Multiple Workloads

I encourage you to watch great video about good practice how to use VMware I/O Analyzer (VMware bundle of IOmeter).

There is mentioned very important step to get relevant results. The step is to increase the size of second disk in virtual machine (OVF appliance). Default size is 4GB which is not enough because it hits the cache of almost any storage array and results are unreal and misleading.

Video is here
bit.ly/118kWs1 
or here
http://www.youtube.com/watch?v=zHJr957kN1s&feature=youtu.be

Enjoy.