HP SAN Virtualization Services Platform - Manual (Page 155)

Changing the LUN range
You can change the LUN range for a host, per domain, to ensure that virtual disks presented by a
DPM to a host from two different domains are not presented with the same LUN. You can change the
LUN range for UDH hosts. The default LUN range is 0-255.
To change the LUN range of a host:
1. Right-click the host.
2. Select Manage > Change LUN Range. The Change LUN Range screen appears.
3. In the First LUN field, enter the first of the range of valid LUNs to be assigned to virtual disks
when they are assigned to this host from this SVSP domain.
4. In the Last LUN field, enter the last of the range of valid LUNs to be assigned to virtual disks when
they are assigned to this host from this SVSP domain.
5. Click Next. A confirmation screen appears.
6. Click Finish. The LUN range is set.
Adding and removing host HBAs
Adding and removing host HBAs is supported for UDH hosts. For information about adding and
removing HBAs, see “
Managing host bus adapters ” on page 165.
Managing host online/offline state
Switching a host to an offline state is a way to attempt the recovery of a host that is not functioning
properly. In an offline state, the host is disconnected from the VSM elements to which the host had
permission so that you can perform operations to those elements and present them again to the host.
You can switch a host to the offline state when the host’s status is Absent or Failed. In an offline state,
presentations are removed from the host, and operations on VSM elements to which the host had
permission are saved to the VSM setup database. While a host is offline, VSM does not wait to receive
acknowledge messages from the host on operations performed. When you return the host to the online
state, presentations are restored to the host and the host receives its VSM elements in their new states.
CAUTION:
Before switching the host to the offline state and performing operations on the VSM elements (virtual
disks, VDGs, and snapshots) that belong to the host, shut down the host or disconnect the host from
the SAN. If you do not shut down or disconnect the host, the host may attempt to write to the virtual
disk at the same time that VSM makes changes to the virtual disk structure (deletes a PiT, deallocates
a temporary virtual disk, and so on), which may cause data corruption. Also, by dismounting the
device, the device caches are flushed such that all pending work is sent to the media. Failure to
dismount the device may lead to loss of data.
You can perform the following operations when the host is offline:
• Delete a virtual disk owned by the host.
• Remove permission from a virtual disk.
HP StorageWorks SAN Virtualization Services Platform Manager user guide 155