To modify VCS configuration to enable I/O fencing

1. Save the existing configuration:

   # haconf -dump -makero

2. Stop VCS on all nodes:

   # hastop -all

3. To ensure High Availability has stopped cleanly, run:

   gabconfig -a

   In the output of the commands, check that Port h is not present.

4. If the I/O fencing driver vxfen is already running, stop the I/O fencing driver.

   For RHEL 7, SLES 12, and supported RHEL distributions:

   # systemctl stop vxfen

   For earlier versions of RHEL, SLES, and supported RHEL distributions:

   # /etc/init.d/vxfen stop

5. Make a backup of the main.cf file on all the nodes:

   # cd /etc/VRTSvcs/conf/config
   # cp main.cf main.orig

6. On one node, use vi or another text editor to edit the main.cf file. To modify the list of cluster attributes, add the UseFence attribute and assign its value as SCSI3.

   cluster clus1(
   UserNames = { admin = "cDRpdxPmHpzS." }
   Administrators = { admin }
   HacliUserLevel = COMMANDROOT
   CounterInterval = 5
   UseFence = SCSI3
   )

   Regardless of whether the fencing configuration is disk-based or server-based, the value of the cluster-level attribute UseFence is set to SCSI3.

7. Save and close the file.
8. Verify the syntax of the file /etc/VRTSvcs/conf/config/main.cf:

   # hacf -verify /etc/VRTSvcs/conf/config

9. Start the I/O fencing driver and VCS. Perform the following steps on each node:

   • Start the I/O fencing driver.

     The vxfen startup script also invokes the vxfenconfig command, which configures the vxfen driver to start and use the coordination points that are listed in /etc/vxfentab.

     For RHEL 7, SLES 12, and supported RHEL distributions:

     # systemctl start vxfen

     For earlier versions of RHEL, SLES, and supported RHEL distributions:

     # /etc/init.d/vxfen start

   • Start VCS on the node where main.cf is modified.

     # /opt/VRTS/bin/hastart

   • Start VCS on all other nodes once VCS on first node reaches RUNNING state.

     # /opt/VRTS/bin/hastart