After you configure VCS with the installer, you must configure I/O fencing in the cluster for data integrity. Application clusters on release version 7.2 (HTTPS-based communication) only support CP servers on release version 6.1 and later.
You can configure disk-based I/O fencing, server-based I/O fencing, or majority-based I/O fencing. If your enterprise setup has multiple clusters that use VCS for clustering, Veritas recommends you to configure server-based I/O fencing.
The coordination points in server-based fencing can include only CP servers or a mix of CP servers and coordinator disks.
Veritas also supports server-based fencing with a single coordination point which is a single highly available CP server that is hosted on an SFHA cluster.
You use majority fencing mechanism if you do not want to use coordination points to protect your cluster. Veritas recommends that you configure I/O fencing in majority mode if you have a smaller cluster environment and you do not want to invest additional disks or servers for the purposes of configuring fencing.
If you have installed VCS in a virtual environment that is not SCSI-3 PR compliant, you can configure non-SCSI-3 fencing.
See Figure: Workflow to configure non-SCSI-3 I/O fencing.
Figure: Workflow to configure I/O fencing illustrates a high-level flowchart to configure I/O fencing for the VCS cluster.
Figure: Workflow to configure non-SCSI-3 I/O fencing illustrates a high-level flowchart to configure non-SCSI-3 I/O fencing for the VCS cluster in virtual environments that do not support SCSI-3 PR.
After you perform the preparatory tasks, you can use any of the following methods to configure I/O fencing:
You can also migrate from one I/O fencing configuration to another.
See the Storage foundation High Availability Administrator's Guide for more details.