Disk latencies play a vital role in the performance degradation for any OLTP systems like Microsoft Dynamics AX, D365 and Dynamics CRM. Optimized IO lead to the optimal software performance. Microsoft has set the following threshold for the optimal IO:
If the response times are less than 0.015 (15 milliseconds), then the disk subsystem is keeping up with demand.
If the response times are greater than 0.025 (25 milliseconds), then the disk subsystem is likely overwhelmed.
Most of the performance issues with Microsoft Dynamics lead to either the database or a poorly designed customization. If you are experiencing performance issues then the first thing I suggest you to check is the IO subsystem for any bottleneck. With a standard Microsoft command tool “diskspd” it is now even easier to simulate the actual disk system performance close to the actual usage scenario. This tool can be downloaded this link.
Once you download the tool there is a Word document in the package specifically written to test the IO for the SQL Server. The same document also includes the sample commands. I recommend to test the IO for both 8K and 64K block sizes.
Thank you for taking your time out to read this blog post. I hope you find it to be useful.