Seven Requirements for Virtual Desktop Success


What do you think are the main ingredients to any successful desktop virtualization project?  Is it application integration methodology? Is it hardware? What about the IT team?  Based on my experience, the top requirements really boils down to a few core items, all of which I’ve discussed many times in previous blog postings (applications, standards, and executive buy-in to name a few).

Before we get into the seven requirements, we must understand the point of desktop virtualization.  Continue reading Seven Requirements for Virtual Desktop Success

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This School House Rocks with Virtual Desktops


Imagine an environment where:

  • The endpoints are over 5 years old
  • Users’ personal computers are state of the art
  • Applications have not been patched in over one year
  • Each office has different configurations, although they should be identical

These are some of the challenges with one particular environment: the ABC School District.

This particular school district consists of 50 school campuses that supports 70,000 users.  Due to limited funding, the technology infrastructure is aging quickly.  Thanks to a voter approved tax levy, the ABC School District is receiving an infusion of money to upgrade their computing infrastructure. Instead of going down the same path of distributed computing, the ABC School District has decided to implement desktop virtualization based on the following architecture: Continue reading This School House Rocks with Virtual Desktops

Local or Shared Storage – that is the question


Previously I’ve talked about how using local storage can help reduce the costs of desktop virtualization.  Paul Wilson tested this type of environment to determine if it is possible or to see if I was talking crazy. The result: it is possible and I’m a little crazy.  So we have a new design decision, which way will you go?

Continue reading Local or Shared Storage – that is the question

Dear Architect, is my write cache estimate correct?


The latest question into the Ask the Architect mailbag comes from Andy.  Andy is creating a Provisioning services design for an environment based on Windows Server 2008, with the write cache stored on a NetApp share.  Andy’s question is if the write cache estimates are correct.  Basically, Andy is estimating 650 MB write cache per virtual desktop.  He achieves this by taking the assigned RAM and multiplying it by 25%.

First, using Windows 2008 is great for Provisioning services as this provides the largest system cache for the vDisk, which will speed up delivery as local disk reads are not required as often.

Second, write cache is a tricky thing to determine. You best bet is to set this up and let users go at it for a few days to see what you end up with.  However, that might not be possible.  In that case ou have to remember that the write cache is based on a few things:

  1. Application delivery approach: Streamed apps will impact write cache more than installed apps, which impact the write cache more than hosted apps. I can tell you my streamed Office applications are consuming 300MB of space on my disk (which would mean 300MB of write cache if the application is not pre-cached).
  2. Reboot cycle: If the default behavior is to reboot the virtual desktop upon each logoff, this will keep the write cache small as it is deleted on each reboot.
  3. Pagefile: The pagefile is included within the write cache file.  I’m assuming this is the RAM portion of the formula.
  4. User work flow: What the user does will have an impact on the size.  Many of the apps require writes to the disk. The more apps a user utilizes, the greater the impact on the write cache.

That is just a summary of what is involved.  If you want to see the blackboard discussion, check out the Ask the Architect Write Cache Video.

What do you think? Did I miss anything? How are you estimating your write cache size as part of the design process?

Do you know all that you should know about desktop virtualization


A long time ago, in a blog far, far away, I asked a simple question “What virtual desktop design topics are you interested in?”  Thankfully, I got a few comments from Steven Hunt, Faisal Iqbal, and Tyrone Thomas so I won’t be forced to deliver a standard, glossy marketing presentation.

Instead, those of you attending the “Designing an enterprise-class XenDesktop solution“, which will be presented by myself and Doug Demskis, will get to experience a low gloss, high value session. Doug and I have gathered mountains of feedback from our Citrix consultants and tried to condense it into 90 minutes, which in itself is no small feat because we all know how much consultants like to talk.

A few of the items we plan to cover are

  • Why and how to change XenServer’s Dom0 RAM allocation
  • Recommended specs for a VMware  configuration
  • Sizing guidelines for Hyper-V
  • What types of disks to use
  • How to calculate your IOPS requirements
  • Recommendations on how to manage your desktop images
  • Estimating the size of your write cache
  • How to determine your Provisioning services recommended specs

This is only a portion of what you will learn in the Synergy session.  Doug and I have been digging deep into the inner workings to provide you with the best practices for your XenDesktop environment. Hope to see you there.

Daniel – Lead Architect
Owner of the Virtualize My Desktop site

Clash of the Titans: Users, iPads and IT


The iPad was released, and people were happy.

People brought the iPad to work, and users were excited.

Users connected the iPad to the corporate environment and IT got scared.

If you went to the Apple store and did a demo of the iPad, you might have noticed the installed Citrix Receiver (honestly, did anyone actually demo these things before buying? I bet most of us just bought it without playing around with it). But, let’s say you did demo and you selected the Receiver, what would you have seen? Windows Applications.

Yes, Windows Applications on the iPad.  I admit, that is pretty cool. In fact, why not put Windows 7 on the iPad.  It is possible. I’ve also seen reports that people are now using the iPad at work, although right now it is for minor tasks, but this will only increase.  Chris Fleck recently posted a blog talking about some of the top business use cases for the iPad.  These are great ideas, but before our employees start using a virtual Windows 7 XenDesktop desktop on the iPad for work, we need to get the environment prepared.

These items are HOT.  And you know what happens to new technology? It gets stolen. It gets hacked. First, let’s make sure our environment is secured. Second, let’s give the user the best experience.

To secure the environment, there are a few things that should be done:

  1. Require authentication. Seems pretty obvious, but you can connect to virtualized applications and desktops with anonymous accounts (there are business reasons why, but this is not one of the).  If the iPad is stolen, the thief can only see the Receiver, but cannot log in.
  2. Enable encryption: Citrix can encrypt the communication between the iPad and the virtual desktops/applications with RC5-128bit encryption.  As users will connect over any number of wireless networks, it is recommended that the communication is encrypted from prying eyes.
  3. Disable device mapping: Although some of local iPad objects cannot yet be seen within the virtualized desktops/applications (drives, clipbard, etc), it is recommended to still disable  these features from within the XenDesktop/XenApp farms as a precaution.  The Receiver will go through updates and will add new functionality. You, as the administrator, don’t want to be surprised when users start copying materials to/from their iPads.

By doing these simple items, we can make our iPad connections to Windows 7 desktops and Windows applications more secure. But how do we make the user experience better?  Here are some recommendations:

  1. HDX: Many users will browse web sites on their iPads.  By enabling HDX browser acceleration, we can compress the images and give the user a faster browsing experience.  Also, because the iPad does not support Flash natively, by accessing a hosted browser, users can view websites with integrated flash content. By enabling HDX Flash (Server-side rendering), we can allow users to view flash animation content at reasonable performance levels by slightly degrading the flash quality.
  2. Visual Effects: Windows has many features that provide an interactive experience, but some of these items require additional bandwidth.  For iPad users, it is recommended to disable menu animations and to disable window content while dragging.  This allows the desktop to have faster response times.  Although we can also disable the user’s desktop background, I prefer to keep the backgrounds enabled. Hey, it’s the first thing the user sees that helps create that personalized environment.
  3. Audio: Although we can disable audio, that really diminishes the user experience, especially if we are using a hosted browser so users can access flash content.  Let’s keep audio enabled, but only provide medium sound quality, which will give better performance.

The last thing we must be concerned with is that these settings do not interfere with other users. Not everyone is going to have an iPad.  Even iPad users will still access their virtual desktops/applications over other devices.  We don’t want these security/optimization settings from impacting others.  In order to accommodate iPad users, we need to create a policy with all of these settings and apply the policy to only iPad devices. By filtering on the client name of iPhone* and iPad*, we can accomplish just that.

Remember, it’s a balance between providing an acceptable user experience, while allowing for performance and security.  By tweaking the policy we can provide. So before your first user tries to use the iPad on your XenDesktop and XenApp environments, better get your infrastructure ready. No matter what you do, users will start to use their iPads to change how they access their applications. They iPad might even have an impact on what devices they use to do their work.  To get ready, you need to prepare and secure your environment appropriately.

Daniel Feller
Lead Architect – Worldwide Consulting Solutions
Citrix Systems, Inc.
Blog: Virtualize My Desktop

Desktop Virtualization… The Right Way (Politics and Puppy Chow)


Politics and dog food… some might say they go hand-in-hand (especially if you watched any coverage about the healthcare debate). But politics and dog food are also relevant in most organizations, especially when undertaking a massive restructuring in the way you deliver desktops to users.

Desktop virtualization is not something you can just turn on one day. It takes planning. Although some organizations made the decision to only implement a small-scale, limited virtual desktop environment, the anticipated improvements with such an environment are lost. Instead of having a centrally managed desktop environment, capable of supporting users in all geographies, the small-scale implementation ends up creating more complexity as two different types of desktop environments must now be supported: traditional and virtual.

If the desktop virtualization solution will be a success in the long run, it requires collaboration between multiple IT groups: network engineers, desktop administrators, server specialists, application experts, and the support team. In many organizations, these teams each have their own objectives and responsibilities. Taking on a desktop virtualization project requires time, resources and commitment; something that is unlikely to happen organically.

If done correctly, a desktop virtualization initiative must have executive level buy-in. Only when the executives are on board with the new initiative will all of the pieces fall into place, which includes:

  • IT Collaboration: Once the executives make desktop virtualization a corporate imperative, the IT groups must forgo the day-to-day politics of their own silos and work together to try and come up with a solution that meets the objectives of the business. This will be difficult and involve breaking down the typical barriers between groups, but with a mandate from the highest levels within the organization, the groups will have no alternative but to work together on a common goal.
  • Funding: Desktop virtualization requires the purchase of additional data center hardware, the levels of which are based on the scale, configuration and virtual desktop types delivered. Most departments do not have the financial resources to create a best-of-breed solution for the users, which results in a fragmented solution not meeting the organization’s expectations. However, with the executive buy-in, funding must be made available to upgrade the infrastructure to support the new environment. This funding must include new server hardware, storage infrastructure, management tools, and networking optimizations.
  • Users and Change: Most users hate change, especially when it comes to their desktop.  Change often means downtime, broken applications or lost files. However, this change can be mitigated by hearing first hand from the executives about why the initiative is being undertaken, what the expectations are, and how the users can help make the project a success. In fact, executives should be the first ones embracing the new environments configured in the same way that users will be expected to work.  By watching the leaders eat the puppy chow, users are more inclined to believe that the new solution is the right thing for them.

With all of the talk about dog food, I think I’ll buy some stock in Purina Puppy Chow.

This is Part 7 in the Desktop Virtualization… The Right Way series:

  • Migration
  • User Experience
  • User Topology
  • Standards
  • Storms
  • Applications

Daniel Feller
Lead Architect – Worldwide Consulting Solutions
Citrix Systems, Inc.
Blog: Virtualize My Desktop