Server and Storage I/O Benchmark Tools: Microsoft Diskspd (Part I)

server storage I/O trends


This is part-one of a two-part post pertaining Microsoft Diskspd.that is also part of a broader  series focused on server storage I/O benchmarking, performance, capacity planning, tools and related technologies.


You can view part-two of this post here, along with companion links here.


Many people use Iometer for creating synthetic (artificial) workloads to support benchmarking for testing, validation and other activities. While Iometer with its GUI is relatively easy to use and available across many operating system (OS) environments, the tool also has its limits. One of the bigger limits for Iometer is that it has become dated with little to no new development for a long time, while other tools including some new ones continue to evolve in functionality, along with extensibility. Some of these tools have optional GUI for easy of use or configuration, while others simple have extensive scripting and command parameter capabilities. Many tools are supported across different OS including physical, virtual and cloud, while others such as Microsoft Diskspd are OS specific.


Instead of focusing on Iometer and other tools as well as benchmarking techniques (we cover those elsewhere), lets focus on Microsoft Diskspd.


server storage I/O performance

What is Microsoft Diskspd?


Microsoft Diskspd is a synthetic workload generation (e.g. benchmark) tool that runs on various Windows systems as an alternative to Iometer, vdbench, iozone, iorate, fio, sqlio among other tools. Diskspd is a command line tool which means it can easily be scripted to do reads and writes of various I/O size including random as well as sequential activity. Server and storage I/O  can be buffered file system as well non-buffered across different types of storage and interfaces. Various performance and CPU usage information is provided to gauge the impact on a system when doing a given number of IOP's, amount of bandwidth along with response time latency.

What can Diskspd do?


Microsoft Diskspd creates synthetic benchmark workload activity with ability to define various options to simulate different application characteristics. This includes specifying read and writes, random, sequential, IO size along with number of threads to simulate concurrent activity. Diskspd can be used for testing or validating server and storage I/O systems along with associated software, tools and components. In addition to being able to specify different workloads, Diskspd can also be told which  processors to use (e.g. CPU affinity), buffering or non-buffered IO among other things.

What type of storage does Diskspd work with?


Physical and virtual storage including hard disk drive (HDD), solid state devices (SSD), solid state hybrid drives (SSHD) in various systems or solutions. Storage can be physical as well as partitions or file systems. As with any workload tool when doing writes, exercise caution to prevent accidental deletion or destruction of your data.

What information does Diskspd produce?


Diskspd provides output in text as well as XML formats. See an example of Diskspd output further down in this post.

Where to get Diskspd?


You can download your free copy of Diskspd from the Microsoft site here.


The download and installation are quick and easy, just remember to select the proper version for your Windows system and type of processor.


Another tip is to remember to set path environment variables point to where you put the Diskspd image.


Also stating what should be obvious, don't forget that if you are going to be doing any benchmark or workload generation activity on a system where  the potential for a data to be over-written or deleted, make sure you have a good backup and tested restore before you begin, if something goes wrong.

New to server storage I/O benchmarking or tools?


If you are not familiar with server storage I/O performance benchmarking or using various workload generation tools (e.g. benchmark tools), Drew Robb (@robbdrew) has a Data Storage Benchmarking Guide article over at Enterprise Storage Forum that provides a good framework and summary quick guide to server storage I/O benchmarking.


Via Drew:


Data storage benchmarking can be quite esoteric in that vast complexity awaits anyone attempting to get to the heart of a particular benchmark.


Case in point: The Storage Networking Industry Association (SNIA) has developed the Emerald benchmark to measure power consumption. This invaluable benchmark has a vast amount of supporting literature. That so much could be written about one benchmark test tells you just how technical a subject this is. And in SNIA’s defense, it is creating a Quick Reference Guide for Emerald (coming soon).


But rather than getting into the nitty-gritty nuances of the tests, the purpose of this article is to provide a high-level overview of a few basic storage benchmarks, what value they might have and where you can find out more.


Read more here including some of my comments, tips and recommendations.


In addition to Drew's benchmarking quick reference guide, along with the server storage I/O benchmarking tools, technologies and techniques resource page (here), check out this companion post as a primer for benchmarking and associated topics titled Server and Storage I/O Benchmarking 101 for Smarties.

How do you use Diskspd?

Tip: When you run Microsoft Diskspd it will create a file or data set on the device or volume being tested that it will do its I/O to, make sure that you have enough disk space for what will be tested (e.g. if you are going to test 1TB you need to have more than 1TB of disk space free for use). Another tip is to speed up the initializing (e.g. when Diskspd creates the file that I/Os will be done to) run as administrator.


Ok, nuff said (for now)


Cheers gs