The decoupling of storage from compute allows Hadoop virtualization to become a viable option, we no longer have a dependency on virtualized storage resource which limited the deployment of the HDFS storage services. With the storage being deployed on Isilon the ability to build the compute and management services for Hadoop in virtual machines becomes possible and brings with it many of the benefits of virtualization. In this paper, I outline the functional deployment architecture for using VM’s with Isilon OneFS.

http://www.emc.com/collateral/white-papers/hadoop-deployments-with-isilon-one-fs-storage.pdf