I created a 1TB iSCSI LUN on my QNAP and installed Open-iSCSI on the Master Node. Open-iSCSI works great! The master node was able to discover the LUN and log in to the iscsi portal. I used the standard Linux type 83 partitioning and created a XFS filesystem on it. A mount point of /export/sdb1 was created and iscsi was updated to automatically start at boot. Next: install GlusterFS and configure the master node.