Review the following guidelines to use the vxfentsthdw utility:

• The utility requires two systems connected to the shared storage.

  Caution:

  The tests overwrite and destroy data on the disks, unless you use the -r option.

• The two nodes must have ssh (default) or rsh communication. If you use rsh, launch the vxfentsthdw utility with the -n option.

  After completing the testing process, you can remove permissions for communication and restore public network connections.

• To ensure both systems are connected to the same disk during the testing, you can use the vxfenadm -i diskpath command to verify a disk's serial number.

  See Verifying that the nodes see the same disk.

• For disk arrays with many disks, use the -m option to sample a few disks before creating a disk group and using the -g option to test them all.

• The utility indicates a disk can be used for I/O fencing with a message resembling:

  The disk /dev/rhdisk75 is ready to be configured for 
  I/O Fencing on node galaxy

  If the utility does not show a message stating a disk is ready, verification has failed.

• If the disk you intend to test has existing SCSI-3 registration keys, the test issues a warning before proceeding.