SAN Volume Controller: Best Practices and Performance Guidelines

Chapter 5.12.1. Approximations

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80 SAN Volume Controller: Best Practices and Performance Guidelines nodes and the controllers. Both rates are considered when monitoring storage controller performance. The two most important metrics when measuring I/ O subsystem performance are response time in milliseconds and throughput in I/ Os per second ( IOPS): Response time is measured from where commands originate and in non- SVC environments. With the SVC, we not only have to consider response time from the host to the SVC nodes, but also from the SVC nodes to the storage controllers. Throughput, however, can be measured at a variety of points along the data path, and the SVC adds additional points where throughput is of interest and measurements ...