Category Archives: Microsoft

Storage Quality of Service (QoS) In Windows Server 2012 R2

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In Windows Server 2012 R2 Hyper-V we have the ability to set  quality-of-service (QoS) options for a virtual machine at the virtual disk level. There is no QoS (yet) for shared VHDX, so it’s a per individual VM, per virtual hard disk associated with that virtual machine setting for now.

What can we do?

  • Limit – Maximum IOPS
  • Reserve – Minimum IOPS threshold alerts
  • Measure – New Storage attributes in VM Metrics

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Limit

Storage QoS allows you to specify maximum input/output operations per second (IOPS) value for a virtual hard disk associated with virtual machine. This puts a limit on what a virtual disk can use. This means that one or more VMs cannot steal away all IOPS from the others (perhaps even belonging to separate customers). So this is an automatic hard cap.

Reserve

We can also set a minimum IOPS value. This is often referred to as the reserve. This is not hard minimum. Here’s a worth of warning, unless you hopelessly overprovision your physical storage capabilities (ruling out disk, controller issues, HBA problems & other risks that impact deliverable IOPS) and dedicate it to a single Hyper-V host with a single VM (ruling out the unknown) you cannot ever guarantee IOPS. It’s best effort. It might fail but than events will alert you that things are going south. We will be notified when the IOPS to a specified virtual hard disk is below that reserve you specified?that is needed for its optimal performance.  We’ll talk more about this in another blog post.

Measure

The virtual machine metrics infrastructure have been extended with storage related attributes so we can monitor the performance (and so charge or show back).  To do this they use what they call “normalized IOPS” where every 8 K of data is counted as one I/O. This is how the values are measured and set. So it’s just for that purpose alone.

  • One 4K I/O = 1 Normalized I/O
  • One 8K I/O = 1 Normalized I/O
  • One 10K I/O = 2 Normalized I/Os
  • One 16K I/O = 2 Normalized I/Os
  • One 20K I/O = 3 Normalized I/Os

A Little Scenario

We take IO Meter and we put it inside 2 virtual machines. These virtual machine reside on a Hyper-V Cluster that is leveraging shared storage on a SAN. Let’s say you have a VM that requires 45000 IOPS at times and as long as it can get that when needed all is well.

All is well until one day a project that goes into production has not been designed/written with storage IOPS (real needs & effects) in mind. So while they have no issue the application behaves as a scrounging hog eating a humongous size of the IOPS the storage can deliver.

Now, you do some investigation (pays to be buddies with a good developer and own the entire infrastructure stack) and notice that they don’t need those IOPS as they:

  1. Can do more intelligent data retrieval slashing IOPS in half.
  2. They waste 75% of the time in several suboptimal algorithms for sorting & parsing data anyway.
  3. The number of users isn’t that high and the impact of reducing storage IOPS is non existent due to (2).

All valid excuses to take the IOPS away …You think let’s ask the PM to deal with this. They might, they might not, and if they do it might take time. But while that remains to be seen, you have a critical solution that serves many customers who’re losing real money because of that drop in IOPS has become an issue with the application. So what’s the easiest thing to do? Cap that IOPS hog! Here the video on how you deal with this on Vimeo: http://vimeo.com/82728497

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Now let’s enable QoS as in the screenshot below. We give it a best effort 2000 IOPS minimum and a hard maximum of 3000 IOPS.

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The moment you click “Apply” it kicks in! You can do this live, not service interruption/ system downtime is needed.

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I actually have a hard cap of 50000 on the business critical app as well just to make sure the other VMs don’t get starved. Remember that minimum is a soft reserve. You get warned but it can’t give what potentially isn’t available. After all, as always, it’s technology, not magic.

In a next blog we’ll discuss QoS a bit more and what’s in play with storage IO management in Hyper-V, what the limitations are and as such we get an idea what Microsoft should pay attention to vNext.

Remarks

Well doing this for a 24 node Hyper-V cluster with 500 VMs could be a bit of challenge.

2014 Kicks Offs With A Microsoft MVP Award Renewal!

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I can start of the new year at the office tomorrow by whishing everyone a great 2014 and talking to the CEO about making sure we schedule/budget for the MVP Summit in 2014 as I just got this e-mail in:

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This is great news. Somewhere this month, a box will arrive at my house with a new ring for the award trophy and a new MVP Certificate. The trophy itself stands proudly on a cupboard in my parents living room. I might have earned the award, but they made sure I was given the little backpack with the values & the education to make that possible. And while they don’t really understand the technicalities of what I do, they think the world of it when I fly of to the USA because Microsoft likes to talk to me Smile.

While you get the MVP award for contributions over the past year to the community you must realize that being active in the community is a very rewarding endeavor in itself. No, it’s not like you can put a hard dollar amount on it, nor want to. The value is that you help out a lot of people and in return effectively crowd source your IT issues to a global community. It help other and yourself learn and grow. We constantly need to figure out a lot of things in our line of business. Studying, thinking, analyzing, designing, implementing & supporting a wide ever changing IT stack is not a one person or one team job. Sharing insights & experiences (both good and bad) with your peers helps a lot. You grow a global network of highly motivated, experienced & skilled people. A network you can leverage & consult when you need it. A network that you contribute to when you can, where you can. That’s what it’s about. The cost of participating is dwarfed by the return as many hand help make hard work easier. Good bosses & smart organizations have figured this out. During a panel discussion at Dell World Jonathan Copeland used the metaphor that it take a village to raise a kid. I added to it that one day that kid needs to leave the village and go out into the world. Being active in communities helps with both. I’ve also talked about this here.

I’m very happy with my 2014 MVP Award. I cherish the interaction with my fellow MVPs and Microsoft. The 2014 MVP Global Summit is already on my agenda. I’m grateful for the opportunities it brings and the continuous privilege of learning & sharing. See you all on line, at conferences, think tanks & community events & in Bellevue/Redmond.

DELL World 2013 – Tour Of the Acoustic & Storage Testing Labs & Presenting at the Dell TechCenter User Group

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While at Dell World 2013, a group of us had the opportunity to visit the Dell offices as part of the Trends in Data Center Technology Think Tank. We saw advancements in fresh air cooling, a hot house,

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the storage lab and, new to me, the acoustic labs. Below is a picture of Chris Peterson, the acoustic Architect (he was involved in the design of the DELL VRTX, which is a unique solution and achievement in the industry). Like wise the also have thermal engineers and both of these expertises are closely related.

I will never look at acoustic / thermal engineering for servers & storage in the same way I used to and I have way more respect for the effort and a better understanding of what efforts go in to this research and why.

For some more information on the acoustic lab read this white paper Dell Enterprise Acoustics and watch these videos:

Dell thermal & acoustic engineers discussing the VRTX
Chris Peterson on Dell PowerEdge Generation 12 Server acoustics

Next to all that I attended briefings, had one to one conversations with network, storage & server managers & engineers. I had a lot of information, questions & request to share from our Microsoft MVP Community in regards to our needs & wishes for the best possible support for Windows Server 2012 R2, Hyper-V, ODX, UNMAP, SMB Direct, SOFS, Management & cloud. I even jumped into an open source breakfast discussion on * cloud computing. Last but not least we joined fellow Rock Stars Jonathan Copeland (@VirtSecurity), Rasmus Haslund (@haslund) & Dell Tech Center’s community manager Jeff Sullivan (@JeffSullivan) to discuss what community & social media means to us.

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I also shared our experiences with Windows Server 2012 R2, Hyper-V, DVMQ, vRSS & ODX at the Dell Tech Center User Group during Dell World 2013.

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Want to talk and demo DVMQ & vRSS? Start with the basics: RSS Smile 

To all my community buddies a very festive end of the year and a great 2014! If you want to know even more about how rewarding being part of a community can be, check out this blog Mindset of the community by Marc van Eijk (@_marcvaneijk)

TechNet Top Support Solutions From Microsoft Support Blog

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As this year comes to an end I’d like to draw your attention to Microsoft’s new Top Support Solutions blog on TechNet. It was created this as part of their continuous efforts to keep the various  technical communities informed about the most relevant answers to the top questions or issues experienced with their products. They identify these top issues by analyzing the question in their forums and their other support channels.

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So if you need to find answers for your self or your customers go take a look at the "Top Solutions Content" blog. Changes are you’ll find valuable information about the Microsoft top support solutions for several of their popular products in Server and Tools. It might save you and your clients or manager a lot of time, effort and money. It’s also a great resource to make your colleagues, community, user group or clients aware of.