I/O fencing protects the data on shared disks when nodes in a cluster detect a change in the cluster membership that indicates a split-brain condition.
This decision prevents possible data corruption. The installer installs the I/O fencing driver, VRTSvxfen, when you install SF Oracle RAC. To protect data on shared disks, you must configure I/O fencing after you install and configure SF Oracle RAC.
I/O fencing technology uses coordination points for arbitration in the event of a network partition.
I/O fencing coordination points can be coordinator disks or coordination point servers (CP servers) or both. You can configure disk-based or server-based I/O fencing:
See About preventing data corruption with I/O fencing.
See the Veritas Storage Foundation for Oracle RAC Installation and Configuration Guide.