Do I need a special HBA to run iSCSI?
Not necessarily, but it depends. iSCSI can be used over a standard TCP/IP link with your existing Ethernet adapter if you have a software iSCSI driver installed. A dedicated iSCSI HBA can improve performance. Some operating systems do not have software-only iSCSI drivers available, in which case, a special iSCSI HBA might be the only choice.