can you test if you can format your LUN with VMFS and create some files / a virtual machine there? So we can make sure that the ESXi can theoretically communicate with the luns/disks/
Usuallay a RDM is not supported with local-attached-storage. They shouldn't even get shown to you in the list of lun when you add the RDM. (unsupported workaround would be here: http://blog.davidwarburton.net/2010/10/25/rdm-mapping-of-local-sata-storage-for-esxi/ )