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18 Best Practices for Deploying a Mixed 1Gb/10Gb Ethernet SAN using Dell Storage PS Series Arrays | BP1008
4.3 Analysis of pool design and architecture test results
For 1Gb host initiators, it is apparent that the placement of volumes in either separate, single speed pools or a
single mixed speed pool results in very little performance change. However, 1Gb host initiators that will be
migrated to 10Gb host initiators in the future need to be considered. For hosts that will be migrated, the
recommendations for 10Gb initiators should be followed. The performance at the 1Gb level would not be
affected for these migrated hosts, but configuring for 10Gb connectivity initially would avoid the need to either
recreate volumes on or migrate volumes to 10Gb arrays when the host initiator migration occurs.
The second question of whether 1Gb initiators will benefit from accessing 10Gb volumes is also answered
positively. No matter the decision on placement of volumes, performance increases can be achieved by
accessing new volumes on the 10Gb arrays.
For 10Gb initiators, the placement of those volumes in separate speed pools is much more critical. As seen in
the test results, accessing data located only on 1Gb arrays from a 10Gb initiator results in much lower
performance. Because of this, accessing volumes on separate speed pools is less affected than accessing
volumes on mixed speed pools. Additionally, performance penalties from accessing the lower speed arrays
would likely be worsened when multiple 10Gb initiators are in play. This is especially true of latency and TCP
retransmits.