Why can't I add a Red Hat Storage volume as a storage domain in my RHEV environment?

Issue

• Attempting to add a RHS volume as a data storage domain in a RHEV 3.1 environment
• Process is failing with the following error message:

StorageDomainFSNotMounted and error message VDSGenericException: VDSErrorException: Failed to CreateStorageDomainVDS, error = Storage domain remote path not mounted: ('/rhev/data-center/mnt/rhs1.redhat.com:_vmstore',)
2013-04-12 11:47:56,326 INFO  [org.ovirt.engine.core.vdsbroker.vdsbroker.BrokerCommandBase] (ajp-/127.0.0.1:8702-12) [dff9b14] Command org.ovirt.engine.core.vdsbroker.vdsbroker.CreateStorageDomainVDSCommand return value 
 Class Name: org.ovirt.engine.core.vdsbroker.vdsbroker.StatusOnlyReturnForXmlRpc
mStatus                       Class Name: org.ovirt.engine.core.vdsbroker.vdsbroker.StatusForXmlRpc
mCode                         360
mMessage                      Storage domain remote path not mounted: ('/rhev/data-center/mnt/rhs1.redhat.com:_vmstore',)


2013-04-12 11:47:56,326 INFO  [org.ovirt.engine.core.vdsbroker.vdsbroker.BrokerCommandBase] (ajp-/127.0.0.1:8702-12) [dff9b14] HostName = rhev1
2013-04-12 11:47:56,326 ERROR [org.ovirt.engine.core.vdsbroker.VDSCommandBase] (ajp-/127.0.0.1:8702-12) [dff9b14] Command CreateStorageDomainVDS execution failed. Exception: VDSErrorException: VDSGenericException: VDSErrorException: Failed to CreateStorageDomainVDS, error = Storage domain remote path not mounted: ('/rhev/data-center/mnt/rhs1.redhat.com:_vmstore',)