Rhev 3.2 I/O scheduler

When it comes to VM's it is important to fine-tune the I/O performance. I know that VMware ESX uses an asynchronous intelligent I/O scheduler. I also know that, when ran, tuned on the VM hosts, it changes the disk I/O scheduler from cfq to deadline, which allows the host to manage the I/O scheduling instead of the VM itself. I should rephrase, allows the host to do the grunt of the work as the host is more aware of its disks. My question expands on the subject to include storage systems. For better performance, when a storage system is attached to the Rhev hosts, what would the I/O scheduler settings should be on rhev?...deadline?...noop???...since the grunt of the work is done by the storage system....e.g EMC, Compellent, etc? Also, when tuning a rhel VM and running "tuned-adm profile virtual-guest" why is the I/O scheduler set to deadline and not noop??
thanks