Installation and Reference Guide for HP MPIO Full Featured DSM for EVA3000/5000 VCS 4.xxx Disk Arrays 3.00.00 (AA-RW8SF-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.

ALB Adaptive Load Bala nce (ALB) is a feature provided by the EVA DSM that utilizes

certain features supported by the array, to deliver better performance for host

I/O requests.

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 e quivalent system

component for

a component that has failed.

HBA Host Bus Adapter. An I/O device that ser ves as the interface conne cting a host

system to the SCSI bus or SAN (Storage Area Network)

host The c omputer 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 c onditions. 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 commun ication route that enables data and com m a nds to pass

between a host server and a storage dev ice.

path state An attribute that describes the operational condition of a path. A path 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 d evice 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.

HP MPIO Full Featured DSM for EVA3000/5000 VCS 4.xxx Disk Arrays 3.00.00