MPIO policy with iSCSI initiator, MD3000i and disk manager

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A MD3000i is used with the iSCSI Windows 2008 R2 initiator and MPIO to provide storage for 2 Hyper-V R2 Share Clustered Volume hosts.

The SAN is connected to 2 different switches (2 Network interfaces / controller)  2 network adapters on each host are connected to the Storage Area Network (total of 8 targets / host)

By default in the Windows iSCSI initiator in the MPIO the least queue Depth policy is selected, Round Robin is also available.  

1 - I'm not sure to know which one is the best to use in that context.  Any advice would be appreciated.  

2 - The only available policy In the Windows disk management properties is Round Robin with Subset.  But it's not selected.  As the Least Queue Depth is already selected in the iSCSI initiator, should I let it empty in the disk management properties ?

3 - I read the difference between all policies on technet.  But I would like to get a better picture on what it does, what is best to use...


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1 -  Least Queue Depth is the best one for performance

"This is an Active-Active policy that provides the most performance benefits. This is achieved by optimizing the distribution of I/O load based on the current outstanding I/O queued at all IT_Nexus, through which a LUN is reachable. Because of the performance benefits provided, this is the default load balancing policy set for Data ONTAP DSM 3.2. This policy tracks the current outstanding I/O queue at all the IT_Nexus and chooses the path with the least I/O outstanding.É

2 - As far as I understand, when Least Queue Depth is already selected in the iSCSI MPIO tab for each target it is the one in used.  Otherwise in switching on Round Robin in disk manager will bypass the policy for the selected LUN.

3 - As said Least Queue Depth offers better performance.

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