VMware I/O Analyzer

VMware I/O Analyzer is an integrated framework designed to measure storage performance in a virtual environment and to help diagnose storage performance concerns. I/O Analyzer, supplied as an easy-to-deploy virtual appliance, automates storage performance analysis through a unified interface that can be used to configure and deploy storage tests and view graphical results for those tests.

https://labs.vmware.com/flings/io-analyzer