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Verifying fenced configurations

Administrators can use the vxfenadm command to test and troubleshoot fenced configurations. The vxfenadm command includes the following options:

-d	Display current I/O fencing mode
-g	Read and display keys
-i	Read SCSI inquiry information from device
-m	Register with disks
-n	make a reservation with disks
-p	Remove registrations made by other systems
-r	Read reservations
-x	Remove registrations

Formatting the registration key

The key defined by VxVM associated with a disk group consists of seven bytes maximum. This key becomes unique among the systems when the VxVM prefixes it with the ID of the system. The key used for I/O fencing, therefore, consists of eight bytes.

Corrective actions to prevent data corruption describes the keys currently assigned to the disks.

 To display keys currently assigned to disks

• To display keys currently assigned to disks from the system with node ID 1, type the following command:

  # vxfenadm -g /dev/device_name

  Reading SCSI Registration Keys...

  Device Name: device_name

  Total Number of Keys: 1

  key[0]:

  Key Value [Numeric Format]: 65,80,71,82,48,48,48,48

The -g option of vxfenadm displays the eight bytes of a key value in two formats. In the numeric format, the first byte, representing the node ID, contains the system ID plus 65. The remaining bytes contain the ASCII values of the key's letters. In this case, "PGR0000." In the next line, the node ID 0 is expressed as "A" and node ID 1 would be "B."