HP Logical Server Management Best Practices

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Figure 37: Creating a storage entry when defining a virtual machine logical server
The storage is defined within the same portability group as the logical server(s) that will consume the storage. Ports
can be added via the “Add Port” button. The fabric need not be specified as it will be determined by the hypervisor
hosts selected (as with the server WWN values). Volumes are specified with standard attributes such as redundancy,
size, RAID level, and one field unique to VM storage (Access). The Access property defaults to virtual, but can also be
set to physical.
A Raw Device Mapping (RDM) is a file in a VMFS volume that acts as a proxy for a raw device. Virtual mode for a
mapping specifies full virtualization of the mapped device and is more portable across storage hardware than
physical mode, presenting the same behavior as a virtual disk file. Physical mode of a raw device mapping
specifies minimal SCSI virtualization of the mapped device, allowing the greatest flexibility for SAN management
software, and is useful to run SAN management agents or other SCSI target based software in the virtual machine.
As with other storage pool entries, the Storage Port WNN and LUN information must be provided prior to activation.
The information is based on the storage created to fulfill this volume request. If not known at the time the logical server
is being defined, it can be added to the storage pool entry definition later when known.
The Manage Server WWNs table of Figure 37 contains the hypervisors in the portability group, with their various
server HBA initiator WWNs. The Ready checkbox next to each can be selected when the administrator is confident
that the storage has been suitably presented and zoned and is ready for immediate use. When cross-technology
logical servers are used, it is critical that the storage volumes have been presented to all possible targets, and be
presented with the same LUN number and target WWN across all possible targets.