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Realize the Promise of BYOD with the Next Generation Education Workspace

February 6, 2013 at 8:33 pm PST

Can 1 +1 really = 3 (or more)?  Consider the opportunity presented by the thoughtful convergence of BYOD and virtual desktop technologies.

BYOD is one of the most important trends in education technology today. However, many BYOD initiatives are limited to providing personal devices with basic network connectivity via the campus Wi-Fi network. Traditional virtual desktops (VDI) are not new in education. Historically, VDI has allowed the delivery of non-persistent desktops, primarily to thin clients.

Through the Cisco Unified Workspace for Education, schools, colleges and universities can now provide next generation education workspaces that are virtual, social, mobile and collaborative. The Cisco Unified Workspace for Education integrates the Cisco BYOD and Virtualization Experience Infrastructure (VXI) Smart Solutions to provide students, faculty, and staff with the flexibility of using any device to access any information, any application, and any expertise—from anywhere.

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VDI “The Missing Questions” #2: Core Speed scaling (Burst)

Welcome back as we continue to dive deeper into advanced CPU (Central Processing Unit -- I had a “tech writer” change a document on me one time, he assumed at this day in age that people still needed to have the CPU acronym translated.. but I digress) and Memory concepts in the land of VDI. Last week Doron answered our first question and told us about Core Count vs. Core Speed for scalable VDI. This week we will focus specifically on Core Speed, bursting and introduce you to a potentially new subject called “SPEC Blend/Core” for high performance VDI. If you are just finding this blog post for the first time, I encourage you to check out the Introduction from Tony as it will help set the stage for our discussion. Here is the full table of contents:

  1. Introduction – VDI – The Questions you didn’t ask (but really should)
  2. VDI “The Missing Questions” #1: Core Count vs. Core Speed
  3. VDI “The Missing Questions” #2: Core Speed Scaling (Burst)  YOU ARE HERE!
  4. VDI “The Missing Questions” #3: Realistic Virtual Desktop Limits
  5. VDI “The Missing Questions” #4: How much SPECint is enough
  6. VDI “The Missing Questions” #5: How does 1vCPU scale compared to 2vCPU’s?
  7. VDI “The Missing Questions” #6: What do you really gain from a 2vCPU virtual desktop?
  8. VDI “The Missing Questions” #7:  How memory bus speed affects scale
  9. VDI “The Missing Questions” #8: How does memory density affect VDI scalability?
  10. VDI “The Missing Questions” #9: How many storage IOPs?

You are Invited!  If you’ve been enjoying our blog series, please join us for a free webinar discussing the VDI Missing Questions, with Tony, Doron, Shawn and Jason!  Access the webinar here!

VM’s are only as fast as their individual cores! Lets look at what this statement means. Example: Assume we have a 1GHz x 4 core processor (hey, it makes math easy for me). When we carve up a server VM or in this case a VM to be used for VDI, we can’t just give it 2 vCPU’s and say it’s got a 2GHz processor. The reality is that it has a dual 1GHz processor. This becomes an important concept in VDI when you are considering the quantity and QUALITY of vCPU’s you allocate to a Virtual Machine and ultimately the end user applications efficiency and the overall scalability of the server platform. This is not a Uni-processor vs. Multi-processor application discussion. We could easily have a very long discussion and debate on the in’s and out’s of application level efficiencies and the Operating Systems ability (and sometimes inability) to properly manage multiple CPU’s. We are going to expand upon the two CPU’s we tested and dig into per core performance.

CPU Burst vs. CPU Reservation. Let’s play around with our example 1GHz x 4 Core Processor a bit more. If we take this single processor and deploy 8 single vCPU desktops on it we will have a 500MHz CPU reservation per VM. The calculation for that is simple 1GHz x 4 Cores = 4,000MHz / 8 total VM’s = 500MHz/VM Reservation. So the Reservation is simply the average amount of CPU that is available to each VM (assuming everything is prioritized equally). But our Burst is different. Our Burst represents the maximum amount of CPU Core that any one VM could ever utilize. In this example, the Burst per VM is equivalent to 1GHz.

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VDI “The Missing Questions” #1: Core Count vs. Core Speed

January 31, 2013 at 8:40 am PST

Choosing the right compute platform for your VDI environment requires both science and art. You have to balance CPU and memory characteristics against your expected workload profile and your desired density. At the end of the day, VDI has to meet some cost criteria in order to go from a fun science project to a funded program in your company. That means you can’t just throw the top bin CPU at the problem; you have to pick the right CPU. This is further complicated by the fact that there is not one CPU that is ideal for all VDI workloads. There is no magical bill of materials at the end of this series of blogs, but we will attempt to make your VDI decisions based more on science than art.

Strength in numbers? Or strength in speed? As Tony said in his introduction, we had several involved questions related to VDI that we honestly couldn’t answer… so we decided to start testing. This will be a series of blogs that attempts to answer practical questions like “when is processor A better than processor B?” And of course you then have to ask “when is processor B better than processer A?” In this first installment in the series, I will tackle the question of whether the number of cores or the core speed is more important when the goal is to achieve the best desktop density per host. Here is a handy guide to the other posts in this series:

The usual suspects. Throughout this series, we will focus on two processors. We picked them because they are popular and cost effective, yet quite different from each other. They are not top bin processors. Take a look at the table below for a comparison.

Note: Prices in this table are recommended prices published by Intel at http://ark.intel.com and may vary from actual prices you pay for each processor. The SPEC performance numbers are an average of SPEC results published by many OEMs (at http://www.spec.org/) across many platforms. These are not Cisco-specific SPEC numbers.

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Zero to 5000 Citrix VDI Users Logged-in and Working in Just 30 Minutes!

Making sure your users don’t go to sleep (or worse) waiting to log-on
Hi Everyone! I am the team lead Technical Marketing Engineer for Cisco Virtual Desktop Infrastructure (VDI) solutions on UCS and Nexus. While I have done some blogging in my time – this is my first blog for Cisco. I have been in this space for over 22 years, before “virtualization” was called that, working with published applications and published desktops (MetaFrame and early RDP.)
With the Citrix and EMC teams, I have been focused for the past few months on validating what I think is a really exciting solution -- even if I say so myself. So recently not much time for blogging I am afraid.
Over the last couple of years we have seen desktop virtualization, specifically Hosted Virtual Desktops (HVD,) become increasingly more mainstream -- but today we are really experiencing an upsurge of deployments -- and not just pilots -- but full blown multi-thousand seat deployments.
As you are probably aware the worst nightmare is that you deploy the solution and the users don’t adopt it because it doesn’t provide them the user experience they need or want.
One of the key requirements for success is an infrastructure that won’t just provide the right experience for the first few hundred users -- but that will scale linearly as you grow into the many thousands.
You can rely on Cisco Validated Designs to deliver for you! We use real world test scenarios to insure that you can implement our designs in your environment and be successful.
The keys to a successful deployment of a large scale HVD environment start with:

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VDI – The Questions You Didn’t Ask (But Really Should)

There’s no shortage of content out there (a quick Google search easily confirms this) when it comes to looking for vendor-originated material touting the latest server performance benchmarks for hosted virtual desktops.  Being part of that community, I’m pretty sure I have my fingerprints on more than one such piece of collateral – and I’m constantly reminded of this, when we run into questions along the lines of “yeah, {xxx} desktops on a blade is great, but c’mon, you and I both know we’d never do that in practice”.  It’s a balancing act of demonstrating solution performance, intersected with the practical reality of what IT managers would reasonably support in a production environment.

So what really matters?  If I’m implementing VDI for the 1st time, and I’m trying to make intelligent decisions around CPU, memory speed, IOPS, etc., where do I go?  VDI is unique in its consumption of compute, storage and network resources, when compared to other workloads hosted in the data center.  Much of the performance benchmarking info put out by server manufacturers is not specific to VDI performance, or how user experience might be impacted by simple decisions like choice of clock speed or # of vCPU.

Thankfully, there are folks in my company that care a LOT about such questions.  So much so, that a small, VDI-proficient group of them took it upon themselves to design and build an in-house lab environment with one express purpose – exhaustively exploring and documenting the performance and scalability impacts seen when configuring your compute platform for VDI.  No stone left unturned – things like CPU cores, clock speed, memory speed,  vCPU, memory density and more – all fair game.

The findings are extremely valuable to anyone deploying VDI, and what this team discovered is a set of real-life “questions”.  The “Missing” questions if you will – those questions that are noticeably absent or never sufficiently exposed in marketing materials, when it comes to the practical choices you can make that most significantly impact the cost, scalability and performance of your virtual desktop implementation.

So let me start with an introduction.  Over the next few weeks, you’re going to hear from some peers of mine – Doron Chosnek, Jason Marchesano, and Shawn Kaiser.  They’re Cisco Consulting Systems Engineers, and they live and breathe VDI (I know, melodramatic), as implemented in their customers’ data centers around the world.

They undertook this journey with the express purpose of answering the “missing” questions, by assembling a test platform in their lab, built on Cisco Unified Computing System (UCS), using readily available components including:

  • Various UCS B200 M3 configurations
  • Login Virtual Session Indexer (Login VSI) 3.6.1 benchmark
  • Login VSI’s Medium with Flash workload
  • VMware View 5.1.1
  • Microsoft Windows 7 SP1 32-bit virtual desktops
  • Pure Storage FlashArray with Purity version 2.0.2.

Keep in mind that their goal was not to explore maximum scalability, or prescribe a preferred design/architecture, or even what kind of server blade or processor you should use for VDI.  Instead they relied on commonly available gear easily found in our customer’s data centers.  If you want prescriptive design guidance, Cisco CVD’s are ideal for that, and you can find them here.

So let’s talk about their test environment.

Physical Lab

The physical environment shown below is a highly overprovisioned system.  Only one B200 M3 blade was tested at any one time, yet every logical link between elements shown consists of multiple 10-GbE links or multiple 8-Gb Fibre Channel links.

The storage array has 24 flash disks and is capable of substantially higher IOPS than used for this testing. All the infrastructure machines used for this test (Active Directory, VMware vCenter, VMware View, VSI Launchers) are virtual machines on the B230 M2 blade in the environment.

9 Q Figure 1

 

Note: At the time of testing, the Pure Storage had not completed UCS certification testing.

 

Logical Server Environment

9 Q Figure 2

The tests involved two UCS B200 M3 blades, one with dual E5-2665 processors and the other with dual E5-2643 processors.  The 2643 is a 4-core high clock/burst speed processor, and the 2665 is an 8-core medium/high clock/burst speed processor.  Here are the specs for the CPU’s chosen:

9 Q Figure 3

Now, you may wonder, are either of these THE processor you would choose for VDI?  Not necessarily! 

Keep in mind the goal we set out with – to expose the relative impacts of # cores, clock speed, memory speed, #vCPU’s etc.  What you’ll take away from the results, are guidance on which parameters matter for specific types of VDI deployments.  You can then safely look at a VDI-“workhorse” processor like the E5-2680 or E5-2690, and apply what our CSE’s have learned through this testing, to that class of CPU, and make your best selection there.

The tests were conducted using Login VSI’s Medium with Flash workload generator.  As we explore the test results in this series, you’ll see reference to “VSImax”, which defines the threshold past which the user experience will be unacceptable.  The VSImax threshold will appear on supporting graphs that show the performance curve under various test scenarios.  You can learn more about how this threshold is derived here.

9 Q Table 1

So that’s the test environment.  Through this series – let’s call it VDI – the Questions You Didn’t Ask (But Really Should) – our CSE friends (Shawn, Doron, and Jason) will explore and expose the findings they’ve documented for us, dealing with a new “question” each time.  If you join us for this journey, it’ll be worth your while – you’ll come away with a better appreciation of the impact that some simple decisions in your data center compute configuration can make.

So are you ready for the journey -- You’ll find the Questions (answered thus far) below:

  1. VDI “The Missing Questions” #1: Core Count vs. Core Speed
  2. VDI “The Missing Questions” #2: Core Speed Scaling (Burst)
  3. VDI “The Missing Questions” #3: Realistic Virtual Desktop limits
  4. VDI “The Missing Questions” #4: How much SPECint is enough
  5. VDI “The Missing Questions” #5: How does 1vCPU scale compared to 2vCPU’s?
  6. VDI “The Missing Questions” #6: What do you really gain from a 2vCPU virtual desktop?
  7. VDI “The Missing Questions” #7: How memory bus speed affects scale
  8. VDI “The Missing Questions” #8: How does memory density affect VDI scalability?
  9. VDI “The Missing Questions” #9: How many storage IOPs?
  10. VDI “The Missing Questions” Conclusion

Special Web Event -- You’re Invited!

If you’re enjoying our series, be sure to join our free webcast, where Shawn, Doron and Jason will discuss all the (Missing) VDI Questions Live + take your Q&A.  Access the webcast here.

Featured Whitepaper Now Available!

Need a convenient whitepaper-ized version of the discussion?  Download it now, here.

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