Single Path Implementation; Installation Requirements - HP StorageWorks 4400 User Manual

4 Single path implementation

This chapter provides guidance for connecting servers with a single path host bus adapter (HBA) to
the Enterprise Virtual Array (EVA) storage system with no multipath software installed. A single path
HBA is defined as:
• A single HBA port to a switch with no multipathing software installed
• A single HBA port to a switch with multipathing software installed
HBA LUNs are not shared by any other HBA in the server or in the SAN. Failover action is different
depending on which single path method is employed.
The failure scenarios demonstrate behavior when recommended configurations are employed, as well
as expected failover behavior if guidelines are not met. To implement single adapter servers into a
multipath EVA environment, configurations should follow these recommendations.
The purpose of single HBA configurations for non-mission critical storage access is to control costs.
This chapter describes the configurations, limitations, and failover characteristics of single HBA servers
under different operating systems. Several of the descriptions are based on a single HBA configuration
resulting in a single path to the device, but OpenVMS has native multipath features by default.
NOTE:
Tru64 is not supported with the EVA4400.
With OpenVMS, a single HBA configuration will result in two paths to the device by having connections
to both EVA controllers. Single HBA configurations are not single path configurations with these
operating systems.
In addition, cluster configurations for OpenVMS provide enhanced availability and security. To achieve
availability within cluster configurations, configure each member with its own HBAs and connectivity
to shared LUNs. For further information on cluster configurations and attributes, see the appropriate
operating system guide and the SAN design guide.
NOTE:
HP continually makes additions to its storage solution product line. For more information about the
HP Fibre Channel product line, the latest drivers, and technical tips, and to view other documentation,
see the HP website at
http://www.hp.com/country/us/eng/prodserv/storage.html

Installation requirements

• The host must be placed in a zone with any EVA worldwide IDs (WWIDs) that access storage
devices presented by the hierarchical storage virtualization (HSV) controllers to the single path
HBA host. The preferred method is to use HBA and HSV WWIDs in the zone configurations.
HP StorageWorks 4400 Enterprise Virtual Array user guide 55