Oracle VM Multipath With HP EVA4400/HSV300 San Storage (Doc ID 795426.1)

Last updated on JULY 23, 2013

Applies to:

Oracle VM - Version 2.1.2 to 2.1.2 [Release OVM212]
Information in this document applies to any platform.
***Checked for relevance on 23-Jul-2013***


Goal

To use Oracle VM 2.1.2 with HP EVA4400/HSV300 Storage. 

This storage array has 2 controllers with 2 ports per controller.
The Oracle VM server (Blade Server) has a single dual-port Qlogic HBA.
There are 4 paths to the LUN and the storage is Active/Active - Asymmetrical.
In an Asymmetric Active-Active both controllers are online and both can accept IO, but one controller is assigned as the preferred (owning) controller of the lun.

When the path_grouping_policy in the default multipath.conf was set to 'failover', all IO occurred down a single path (1 HBA port to 1 controller in my storage array).
Example, multipath -ll:

OracleVM (3600508b40008ca650000a00002ce0000) dm-0 HP,HSV300
[size=1.0T][features=0][hwhandler=0]
\_ round-robin 0 [prio=0][active]
\_ 0:0:0:1 sda 8:0 [active][ready]
\_ round-robin 0 [prio=0][enabled]
\_ 0:0:1:1 sdb 8:16 [active][ready]
\_ round-robin 0 [prio=0][enabled]
\_ 1:0:0:1 sdc 8:32 [active][ready]
\_ round-robin 0 [prio=0][enabled]
\_ 1:0:1:1 sdd 8:48 [active][ready]


When path_grouping_policy in the default multipath.conf was set to 'multibus' all IO is spread evenly across all 4 paths.
Example, multipath -ll:

OracleVM (3600508b40008ca650000a00002ce0000) dm-0 HP,HSV300
[size=1.0T][features=0][hwhandler=0]
\_ round-robin 0 [prio=0][active]
\_ 0:0:0:1 sda 8:0 [active][ready]
\_ 0:0:1:1 sdb 8:16 [active][ready]
\_ 1:0:0:1 sdc 8:32 [active][ready]
\_ 1:0:1:1 sdd 8:48 [active][ready]


However, because this is an Active/Active-Asymmetric array, that is not optimal.
IO should be spread across both HBA ports to a single (owning) controller. 
This can be done by using path_grouping_policy to "group_by_prio" in the multipath.conf.

Solution

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