8x00 family of Disk Arrays 3.00.00 Installation and Reference Guide (AA-RW7SJ-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 Balance (ALB) is a feature provided by the EVA DSM that utilizes

certain features suppor ted 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 equivalent system

component for

a component that has failed.

HBA Host Bus Adapter. An I/O device that serves 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 preferre d path fails.

MPIO Multipathing Input/Output.

path A virtual com munication route that enables data and commands to pass

between a host server and a storage device .

path state An attribute that describes the operational condition of a path. A path can exi st

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 L UN.

• Standby —Intermediatestateofthepathbeforeitisinitialized(madeready

for dev ice access), normally will not be seen.

• Failed —PathiscurrentlyunusablefortheI/Ostream.

HP MPIO Full Featured DSM for EVA4x00/6x00/ 8x00 family of Disk Arrays 3.0 0.00