How Can I Best Measure Performance in My Storage Environment?

IOPS (input/output operations per second) is an industry-standard way of measuring disk performance. Typically, the term refers to a sum of data read and write commands to a disk or RAID group for a given period.

Many, if not all, storage arrays have firmware-based mechanisms to measure and report IOPS. Most vendors also offer more comprehensive performance analysis tools as add-on software packages.

Every storage administrator should have a documented process in place to monitor and track IOPS metrics. This can be as simple as a shell script from an array-connected server that queries the array on a regular basis to record IOPS metrics. Or it can be as sophisticated as a comprehensive software package that includes correlation and graphical representation of historical and trend data.

It is also important to understand how the IOPS metrics relate to associated data transfer metrics such as block size, throughput, and response time. It is crucial to correlate and track these metrics in order to truly understand the performance capacity and details of an enterprise storage environment.

Tim Arland, Principal Consultant for Storage Solutions, Forsythe Solutions Group Inc.