IOPS is a metric that indicates the load on a storage array. Our goal in running 16 VMs was to test the scalability of the architecture and maximize IOPS on the XtremIO X2 storage array. We expected the test findings to demonstrate that the XtremIO X2 array can scale to support several SQL Server databases running concurrently with low submillisecond latencies.
The following figure shows the average IOPS test findings for Windows and Linux. The Windows VMs generated 19,700 or more IOPS with an average of 20,500-plus IOPS. Notably, the Linux VMs generated 12,691 or more IOPS with an average of 13,900-plus IOPS—approximately 6,600 fewer average IOPS than that generated by the Windows VMs.
Figure 8. Average IOPS for Windows and Linux VMs
The Benchmark Factor workload configuration was the same between the two operating systems. Nothing in our test data indicates why there was a difference in IOPS between the Windows and Linux VMs. IOPS alone are only an indicator of load on the storage array, and, in this case, the XtremIO X2 array easily supported all the virtualized databases running in parallel.
The eight Windows VMs generated a total of 164,166 IOPS and the Linux VMs generated an additional 111,704 IOPS, for a grand total of 275,870 IOPS on XtremIO X2. The following figure shows the amount of IOPS for each operating system as part of the whole. According to the XtremIO X2 specifications, a fully populated X-Brick module with 72 flash drives supports 220,000 IOPS. In our testing of the reference architecture for SQL Server, the IOPS load exceeded the maximum by 55,870 IOPS.
Figure 9. IOPS per operating system