The DMP Administration Utility --- vxdmpadm

The vxdmpadm utility administers the DMP functionality of VxVM. Refer to the "Administering Dynamic Multipathing (DMP)" chapter in the VERITAS Volume Manager Administrator's Guide, and the vxdmpadm(1M) manual page for detailed descriptions of the options and attributes of this command.

You can use the vxdmpadm utility option listctlr to list all controllers connected to disks that are attached to the host. For example, to list all controllers connected to disks on the host, use the following command:

to display the output from the above command:

This output shows that:

• The first controller c0 is connected to disks that are not under any recognized DMP category.
• The second and third controllers (c1 and c2) are connected to a JBOD (indicated by an enclosure type of "Disk").

All the above controllers are in the ENABLED state which indicates that they are available for I/O operations.

The state DISABLED is used to indicate that controllers are unavailable for I/O operations. The unavailability can be due to a hardware failure or due to I/O operations being disabled on that controller by the System Administrator. The controller state can be changed by using the vxdmpadm utility.

To list all the paths that are connected to a particular controller, you can use the getsubpaths option with the ctlr attribute. For example, use the following command:

to display the output from the above command:

The output display shows the paths that are connected to the controller named c1.

You can use the getsubpaths option combined with the dmpnodename attribute to list all paths that are connected to a LUN (represented by a DMP device). For example, to list information about paths that lead to the LUN named c1t0d0, use the following command:

to display the output from the above command:

The listing above shows that the DMP device c1t0d0 has two paths to it that are named c1t0d0 and c2t0d0. Additional information indicates that only one of these paths is available for I/O operations. One of these paths is in the ENABLED state and the other is in the DISABLED state. Both paths are in a SEAGATE disk array.

To retrieve the name of the DMP device that controls a particular path, the getdmpnode option can be combined with the nodename attribute by using the following command:

to display the output from the above command:

This example output shows that the physical path c1t0d0 is owned by the DMP device c2t0d0, which has two paths to it.