Depending upon what your or somebody else’s definition of a storage hypervisor is, you may or may not be using one or realize it.
If your view of a storage hypervisor is a storage IO optimization technology to address performance and other issues with virtual machines (VMs) and their hypervisors, such as Virsto or ScaleIO along with others, you might be calling those storage hypervisors as opposed to middleware, management tools, drivers, plug-in, shims, accelerators, or optimizers.