In Red Hat Storage 2.0 Plus, it is planned to leverage PosixFS feature in ovirt upstream.
This bug is targeted for RHS 2.0 plus release
This feature has been documented in the Quick Start Guide and is available at the following location: http://documentation-devel.engineering.redhat.com/docs/en-US/Red_Hat_Storage/2.0/html/Quick_Start_Guide/chap-Quick_Start_Guide-Virtual_Preparation.html#sect-Documentation-Quick_Start_Guide-Virtual_Preparation-Prepare_RHS
"Chapter 3. Managing Virtual Machine Images on Red Hat Storage Servers" Verified and is now live.