1. A computing system, comprising: a plurality of virtual machines, including a first virtual machine, and a hypervisor executing on a first host; a storage system comprised of a plurality of physical storage devices that are accessed by the plurality of virtual machines, wherein the plurality of physical storage devices are organized into a storage pool having logical units of storage allocated for storing virtual disks for the plurality of virtual machines, including a first virtual disk for the first virtual machine; and a virtualized disk I/O handler executing on the first host and configured to manage access by the plurality of virtual machines to the storage system, wherein a disk access request for the first virtual disk from the first virtual machine is intercepted and handled by the virtualized disk I/O handler.