HP StorageWorks SAN Virtualization Services Platform Manager user guide (AG781-96017, March 2009)

20. Click Finish. The UDH is created with the parameters you provided, and appears in the hosts list.
Changing the UDH operating system or personality
You can change the operating system or personality of a UDH.
To change the operating system or personality of a host:
1. Right-click the host.
2. Select Manage > Change Features. The Edit Host Parameters screen appears.
3. To change the operating system, select the host’s operating system in the OS type dropdown
box.
4. To change the personality, select the host’s personality in the Personality dropdown box.
5. Click Next. A confirmation screen appears.
6. Click Finish. The operating system or personality is changed.
CAUTION:
Changing the personality disconnects the host from its virtual disks and requires a rediscovery.
Setting the preferred path
A preferred path for a host is a primary path through which virtual disks are presented to the host.
You can set a preferred path for hosts with each of the following agent types:
• No Agent (UDH)—The HP SVSP requires that all UDHs be connected to more than one DPM and
running multipath software. Therefore, the preferred path specifies a primary DPM for presenting
all assigned virtual disks to the host.
• No Agent (HBA)—For a host that represents an HBA exposed to VSM through DPMs, setting the
preferred path sets the primary DPM that presents virtual disks to the HBA.
If no preferred path is set for UDH hosts, VSM distributes virtual disks evenly between DPMs for static
load balancing. The first virtual disk that is assigned permission to the host is presented by the first
DPM. The next virtual disk is presented by the second DPM that supports the configuration. When
you assign host permission to a VDG, all members of the VDG are assigned to use the same DPM.
All subsequent virtual disks assigned permission to the host will be assigned to the other DPM, until
they both service the same number of virtual disks.
Both the preferred path and static load balancing are overridden if you set the primary DPM when
creating a virtual disk or adding host permission to a virtual disk.
NOTE:
You can set a primary DPM for the host for multiple DPM groups by running the Set Preferred Path
wizard multiple times and selecting a different DPM group each time.
To change the preferred path for a host:
1. Right-click the UDH.
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