A split-brain occurs when the cluster membership view differs among the cluster nodes, increasing the chance of data corruption. With I/O fencing, the potential for data corruption is eliminated. I/O fencing requires disks that support SCSI-3 PR.
You can also configure I/O fencing using coordination point servers (CP servers). In virtual environments that do not support SCSI-3, you can configure non-SCSI-3 server-based fencing.
See About server-based I/O fencing.
See About I/O fencing for SFCFSHA in virtual machines that do not support SCSI-3 PR.