Regardless of the underlying storage array, understand the design of the entire application stack and requirements before deployment. This knowledge helps ensure that the PowerStore array is properly sized to deliver the expected performance and capacity. In addition to PowerStore sizing, changes to the infrastructure components such as the storage fabric might also be required. If the application is new, determine application design factors and expected performance metrics before sizing the array and supporting infrastructure.

• Latency: The amount of time that an I/O operation takes to complete. High latencies typically indicate an I/O bottleneck.
• IOPS: The number of reads and writes occurring each second. IOPS is key for determining the number of required disks in an array while maintaining accepted response times. If the array uses SSDs, the array typically provides enough IOPS once capacity and throughput are met. IOPS is a key metric used for designing OLTP databases.
• Throughput: The amount of data in bytes per second transferred between the server and storage array. Throughput is primarily used to define the path between the server and array and the number of required drives. A few SSDs can often meet IOPS requirements but might not meet throughput requirements. Throughput can be calculated as follows using IOPS and the average I/O size: Throughput MBs = IOPS x I/O size.