This figure shows Oracle RAC on an extended distance cluster. The configuration shows three nodes at each of two different locations, Site A and Site B. Below each site, a double-sided arrow links a disk labeled "Oracle RAC Database" to the site above it. Below each database is another disk that contains the Oracle Cluster Registry (OCR)" and "Voting Disk." An arrow between the disk drums indicates that Oracle ASM is used to store the database files.In the center of the figure above Sites A and B is a simple box that represents a third site. The box contains this label: "Third Site for Voting Disk (Mounted by NFS or iSCSI)." All nodes are connected by a redundant public network, a redundant private network, and a redundant storage area network (SAN).