Benefits of SST Vs RR or vice-versa in HP EVA

[Amdocs_case]

Hello All,

In HP EVA we need to set policy which can give better performance. We are planning to set SST policy as suggested by HP but can anyone tell the exact difference between SST & RR policy and which will be more benficial in terms of better performance.

Thanks & regards,
Kavita

[Sivaramakrishna_1]

Hi,

Generally HP MPIO by defaults use SQST. and it is recommanded to enable ALB (Adaptive Load Balance) which eliminates the proxy IO(IO from non-owned controller)

Round Robin (RR): This policy assigns equal priority to all the paths available for a device and routes I/O request to each path in order.

Shortest Queue Service Time (SQST):
This policy selects the path based on the service time for the outstanding I/O requests and chooses the path with
the least outstanding I/O service time for the incoming I/O request. This is the default policy set by the DSM.

For complete reference pls go through the below link:
http://bizsupport2.austin.hp.com/bc/docs/support/SupportManual/c02221077/c02221077.pdf

[Johan Guldmyr]

You want to access the LUNs on the EVA via the owning controller.

The non-owner will pass the request on to the owner anyway.