1. A method for optimizing read operations from a storage device in a virtualized computing environment, the method comprising: monitoring read operations issued by an application running on a virtual machine's (VM) operating system, wherein the VM is hosted by a hypervisor providing access to a storage device in a virtualized computing environment; and causing a virtual file system (VFS) supported by the operating system to call on a first para-virtualized file system (PVFS FE) supported by the operating system to execute a read operation, in response to determining that the read operation is for reading target data from the storage device, wherein if PVFS FE determines that the target data is available in a cache directly accessible by the FVFS FE, then PVFS FE satisfies the read operation by reading the target data from the cache, wherein if PVFS FE determines that the target data is not available in a cache directly accessible by the PVFS FE, then PVFS FE responds to the read operation by forwarding a read request for the target data to a second para-virtualized file system (PVFS BE) supported in the hypervisor, wherein the read request is a file system level request.