HP StorageWorks MSA2012i HP StorageWorks 2000 Modular Smart Array Reference Gu - Page 255

APPENDIX C Host Access to Storage A volume in a virtual disk can be mapped through all controller host ports (target ports) to all data hosts, or through specific controller host ports to specific data hosts. Each mapping between a volume and a data host includes a logical unit number (LUN) that identifies the mapping. This appendix describes how the controllers present volumes to data hosts in direct attach and switch attach configurations, during normal operation and after failover. Failover information only applies to a controller enclosure with two controller modules installed. Note - Host-based multipath software should be used in any configuration where two logical paths between the host and any storage volume may exist at the same time. This would include most configurations where there are multiple connections to the host or multiple connections between a switch and the storage. Topics covered in this appendix are: ■ "Node and Port Identifiers" on page 256 ■ "FC Direct Attach Configuration" on page 258 ■ "FC Switch Attach Configuration" on page 260 ■ "iSCSI Switch Attach Configuration" on page 263 ■ "SAS Direct Attach Configurations" on page 265 255