8x00 family of Disk Arrays 3.00.00 Installation and Reference Guide (AA-RW7SJ-TE, March 2008)

4 Ada ptive Load balance

The HP MPIO EV A DSM implements array speciﬁc load balancing algorithms that utilizes certain features

supported by the disk arrays, to deliver better per formance for host I/O requests. The Adaptive Load

Balance (ALB) setting is suppor ted on a per logical unit basis and works in conjunction with the load

balancing policies supported by the DSM, which includes Round Robin, Shortest Queue Requests,

Shortest Queue B ytes, and Shortest Queue Service Time.

By default, A LB is disabled for the newly discovered LUN. If the newly discovered LUN is part of any

Logical Unit Group, the ALB setting of the existing group prevails.

NOTE:

• AlldevicesthatarepartoftheLogicalUnitGroup,hasthesameALBsetting.

• The ALB set ting is not applicable for devices that have the No Load Balancing policy enabled.

• The ALB setting for a given LUN is persistent across host s ystem reboots.

You can modify (enable/disable) the ALB setting for a given LUN either through the HP MPIO DSM

Manager or the HP DSM CLI. See Managing storage arrays with HP MPIO EVA DSM CLI utility for

more information.

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