Installation and Reference Guide for HP MPIO Full Featured DSM for MSA1000/1500 (Active-Active) Disk Arrays 3.00.00 (AA-RW8AD-TE, March 2008)
Glossary
This glossary defines the terms used in this guide or related to this product. It is not a comprehensive
glossary of computer terms.
controller A hardware device that facilitates communication between a host and one
or more LUNs organized as an array.
DSM Device SpecificModule
fabric A network that contains high-speed fiber connections resulting from the
interconnection of switches and devices. A fabric is an active and intelligent
non-shared interconnect scheme for nodes.
failover The automatic substitution of a functionally equivalent system component for
a component that has failed.
HBA Host Bus Adapter. An I/O device that ser ves as the interface connecting a host
system to the SCSI bus or SAN (Storage Area Net work)
host The computer system on which the Multipath software is running.
LUN LogicalUnitNumber.TheactualunitnumberassignedtoadevicebytheRAID
system controller.
mode A user-selectable parameter that specifies path behavior during normal and
failure conditions. Paths c an be set to one of the following modes:
• Preferred — Indicates the path you choose for the desired I/O paths. When
a path is in preferred mode, load balance is not enabled and the Load
Balance Type displays as none.
• Alternate — Indicates a path that is used for device access and I/O activities
when the preferred path fails..
MPIO Multipathing Input/Output.
path A virtual c om mun ication route that enables data and comma nds to pass
between a host server and a storage device.
path state An attribute that describes the operational condition of a path. A pa th can exist
in one of the following states:
• Active — Path is currently used for the I/O stream or is available for load
balancing.
• Available — Path is currently available, but not used for device access. The
path is only in this state when no load balancing policy has been selected
for the LUN.
• Standby —Intermediatestateofthepathbeforeitisinitialized(madeready
for device access), normally will not be seen.
• Failed —PathiscurrentlyunusablefortheI/Ostream.
port A TherelativenumberofanHBA.Aspecific port number is determined according
to its order of discovery by the Windows operating system. HBA’s include SCSI,
Fibre Channel, and IDE adapter types.
SAN Storage Area Network. A configuration of net worked devices for storage.
HP MPIO Full Featured DSM for MSA1000/1500 (Active-Active) Disk Arrays 3.00.00
45