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)

4 Adaptive Load Balance
The HP MPIO EVA DSM implements array specifi c load balancing algorithms that utilize cer tain features
supported by the disk arrays, to deliver better performance for host I/O requests. The Adaptive Load
Balance (ALB) setting is supported 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 Bytes, and Shortest Queue Service Time.
By default, ALB 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 setting is not applicable for devices that have the No Load Balancing policy enabled.
• The ALB setting for a giv en LUN is persistent across host system reboots.
You can modify (enable/disable) the ALB setting for a given LUN either through the HP MPIO DSM
Manager or HP DSM CLI. See Managing storage arrays with HP MPIO EVA DSM CLI utility for more
information.
HP MPIO Full Featured DSM for EVA3000/5000 VCS 4.xxx Disk Arrays 3.00.00
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