Here is the message I get on the console : Error while executing action Attach Storage Domain: AcquireHostIdFailure
The software seems to go pretty far : it reaches the locked stated before failing.
In engine.log
2013-12-23 16:56:49,497 ERROR [org.ovirt.engine.core.bll.storage.AddStoragePoolWithStoragesCommand] (ajp--127.0.0.1-8702-2) Command org.ovirt.engine.core.bll.storage.AddStoragePoolWithStoragesCommand throw Vdc Bll exception. With error message VdcBLLException: org.ovirt.engine.core.vdsbroker.vdsbroker.VDSErrorException: VDSGenericException: VDSErrorException: Failed to CreateStoragePoolVDS, error = Cannot acquire host id: ('8c626a3f-5846-434e-83d8-6238e1ff9e03', SanlockException(-203, 'Sanlock lockspace add failure', 'Sanlock exception')) (Failed with error AcquireHostIdFailure and code 661)