HP StorageWorks SAN Virtualization Services Platform Manager User Guide (5697-0454, May 2010)

Changing the virtual disk LUN
If a virtual disk is set to allow permission only to UDH hosts, you can change the LUN that the DPM
uses to expose the virtual disk to the host. This option is not available for a virtual disk that belongs
to a VDG or that has components associated with it that were created by VSM services, such as the
snapshot service.
CAUTION:
Changing the value of the logical unit number disconnects the virtual disk from all servers, requires
rediscovery, and remounting by each server that had mounted the device.
To change the LUN of a virtual disk:
1. In the navigation tree, expand the Entities node.
2. Click the Virtual Disk node. The virtual disks list appears in the list area.
3. Right-click the virtual disk for which you want to change the LUN.
4. Select Manage > Manage Permission > Change LUN. The Change LUN wizard opens to the
Select Host(s) screen.
5. In the upper area of the screen, select the host(s) for which you want to change the LUN used by
the DPM to present the virtual disk.
6. Click Next. The Select LUN screen appears.
7. Either select Next free LUN or select a specific LUN from the dropdown list.
8. Click Next. A confirmation screen appears.
9. Click Finish. The LUN with which the virtual disk was presented to the selected hosts is changed.
Managing Data Path Modules
You can set the primary and secondary DPM per virtual disk, and the currently active DPM per virtual
disk.
To load balance the DPMs, distribute the virtual disks by alternating the assignment of the primary
DPM.
Changing the primary and secondary DPM
This option is disabled on an individual virtual disk that belongs to the setup virtual disk or a VDG.
In these cases, the primary and secondary DPMs can be set for the group.
To change the primary and secondary DPM for a virtual disk:
1. In the navigation tree, expand the Entities node.
2. Click the Virtual Disk node. The virtual disks list appears in the list area.
3. Right-click the virtual disk for which you want to change the primary and secondary DPMs.
4. Select Manage > Manage Data Path Module > Change Primary/Secondary Data Path Module.
The Change Primary/Secondary Data Path Module/VSM wizard opens to the Set preferred path
screen.
Working with virtual disks118