Hi,

Just to be clear... you presented the LUN from your SAN to the ESXi hosts.  Then you added a hard disk to your VM using the RDM option and selecting the LUN you previsouly presented to the ESXi host.  You should have a SCSI controller 0 for your VM by default, if you wanted the new hard disk to use a seperate SCSI controller you would have needed to select SCSI (1:0) during the add hard disk wizard.  Is this what you've done and it's not added in another SCSI controller to your VM?

Thanks