Administrators can use the
vxfenadm command to troubleshoot and test fencing configurations.
The command's options for use by administrators are as follows:
Refer to the
vxfenadm(1m) manual page for a complete list of the command options.
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.
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The keys currently assigned to disks can be displayed by using the
For example, from the system with node ID 1, display the key for the disk /dev/rdsk/c2t1d0s2 by entering:
vxfenadm -g /dev/rdsk/c2t1d0s2
Reading SCSI Registration Keys...
Device Name: /dev/rdsk/c2t1d0s2
Total Number of Keys: 1
Key Value [Numeric Format]: 65,45,45,45,45,45,45,45
Key Value [Character Format]: A-------
The -g option of
vxfenadm displays all eight bytes of a key value in two formats. In the numeric format, the first byte, representing the Node ID, contains the system ID 65. The remaining bytes contain the ASCII values of the letters of the key, in this case, "-------." In the next line, the node ID 0 is expressed as "A;" node ID 1 would be "B."
To confirm whether a disk (or LUN) supports SCSI-3 persistent reservations, two nodes must simultaneously have access to the same disks. Because a shared disk is likely to have a different name on each node, check the serial number to verify the identity of the disk. Use the
vxfenadm command with the
-i option to verify that the same serial number for the LUN is returned on all paths to the LUN.
For example, an EMC disk is accessible by the /dev/rdsk/c2t13d0s2 path on node A and the /dev/rdsk/c2t11d0s2 path on node B.
To verify that the nodes see the same disks
vxfenadm -i /dev/rdsk/c2t13d0s2
Vendor id : EMC
Product id : SYMMETRIX
Revision : 5567
Serial Number : 42031000a
The same serial number information should appear when you enter the equivalent command on node B using the /dev/rdsk/c2t11d0s2 path.
On a disk from another manufacturer, Hitachi Data Systems, the output is different and may resemble:
vxfenadm -i /dev/rdsk/c2t0d2s2
Vendor id : HITACHI
Product id : OPEN-3 -SUN
Revision : 0117
Serial Number : 0401EB6F0002
Refer to the
vxfenadm(1M) manual page.