Archive for the ‘Blog Series’ Category

Consolidate for Small Scale

Posted: September 21, 2022 in SMB
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The Ask the Architect email inbox is getting quite large and I’ve received some great questions. I thought I would answer a question around the small-medium business (SMB) space, as it relates directly to a recently delivered Virtual Desktops for the SMB TechTalk and the reference design included within the XenDesktop Design Handbook.

Namely, the SMB white paper focuses on use cases of 200-500 desktops, but what if you only have 50-100 desktops? Do you need all of the servers? Yes in that you will need the components if you plan to do single images but no you won’t need all of the physical hardware. For example, in the reference design, there were the following infrastructure components:

  1. XenDesktop Controller/Web Interface (*2)
  2. Data Store/License Server
  3. Provisioning Server (*2)
  4. NetScaler VPX (*2)

Of course all of these are virtual servers. If we are talking about 50-100 desktops, one virtual server could easily contain items 1, 2, and 3. Ideally, you would have a second VM, on a different physical server, which would contain 1 and 3 to allow you to have some level of fault tolerance (this is a decision you have to figure out). If you don’t need intelligent load balancing, remove the NetScaler VPX. Even if you need secure remote access, you could either get an Access Gateway virtual appliance or run Secure Gateway.

Once that is done, just distribute your windows desktops across the remaining servers.

It basically comes down to this… Nothing is preventing you from putting all of these items on one virtual server. If you are sub-100 desktops, that might be the best way to go to better consolidation. If it was me, I would still follow the guidelines in the TechTalk and white paper as making these separate VMs. You still get consolidation but have greater flexibility for potential future changes and can better optimize the OS for the role it is being asked to do.

Daniel – Lead Architect

One of the big questions regarding virtual desktops is storage. In fact, I’ve discussed this numerous times (here and here and here). This has mostly been with a focus on IOPS. This time I want to focus on the high-availability aspect you get with shared storage, but with the focus of being on the SMB/SME space (small to medium business/enterprise). If you want to do live migration, you must have shared storage. So, let me get straight to the point… You don’t need it. You don’t need XenMotion, vMotion or live migration in a SMB hosted VM-based desktop model. Look at the XenDesktop architecture and let’s focus at the component-level.

  1. Virtual desktops: Desktops are not servers. They aren’t as critical and shouldn’t reflect a higher cost. If the physical server fails, users simply make a new desktop connection.
  2. XenDesktop controller: Always, always, always implement redundant controllers. XenDesktop is smart enough to use a second controller if the primary fails. Is also worthwhile to put intelligent load balancing in front to catch other types of issues that don’t result in complete failure.
  3. Web Interface: Again, use redundant servers, but you need to provide intelligent load balancing so if one fails or goes off into La La Land, you won’t be directed to a bad server.
  4. NetScaler VPX: This is providing our intelligent load balancing mentioned for XenDesktop controllers and Web Interface. Again, implement redundant VPX’s. If you configure these in HA mode, a failure in one means the other one takes over automatically.
  5. Data Store: You can function without the data store, but you can’t make changes. Why not simply create snapshots and revert if needed. Or backup the database and restore if needed. You can even automate this if you want.
  6. License Server: You can function without a license server for 30 days (grace period). If the server is blown up, just rebuild the server and download your licenses (I’d also suggest you figure out why your server is blowing up).
  7. Provisioning Services: If one server fails, the other one takes over the streams automatically. The target desktops might experience a delay during the failover, but they won’t lose anything.

So I ask you, why spend money on SAN storage for virtual desktops in the SMB world if it is just going to cost you more money? Keep it simple

I’ve been part of quite a few desktop virtualization designs in my day. Most of these are for enterprise customers with over 10,000 desktops. When you get to this scale, you have to take into account so many different variables that you need many different options. What about the SMB organizations? The smaller organizations (500 or fewer desktops) probably don’t need as many options and flavors of virtual desktops. In fact, one can create an architecture that meets the needs of the SMB but without all of the components and features. See for yourself by accessing the XenDesktop Design Handbook.

Over the next few weeks, we will have a discussion on this exact topic. What are the design decisions? What are the ramifications of doing and not doing application virtualization? What is the critical path to success? Stay tuned and keep watching the SMB space on the Virtualize My Desktop blog for a great discussion.

Daniel – Lead Architect

The virtual desktop top 10 list is complete! Of course there are numerous things people can do to mess up their environment, but the 10 discussed are probably the 10 most critical. If you get them wrong, you will struggle to survive.

But the list doesn’t end there. My colleagues (Tarkan Koçoglu, Nicholas Rintalan and Doug Demskis) and I couldn’t limit ourselves to just 10 mistakes which is why we have honorable mention status to a few more items J. It’s our way of keeping the top 10 list while allowing ourselves some leeway. Besides, Top 10 is so much better than Top 13 or Top 19 (top 10 has worked for David Letterman for years).

So what are these honorable mentions I speak of?

  • NIC Teaming: Provisioning services streams the desktop image to the virtual desktop. Provisioning services NICs should be teamed for throughput/aggregation and not just for failover/redundancy.
  • NIC Optimization: Although Provisioning services can run with the default NIC configurations, the environment can run faster with optimizations like Disable Large Send Offload
  • Common Image: Reducing the number of images helps simplify management and updates as fewer image updates are required. However, using a single image across multiple physical end point platforms can become difficult to maintain. Specific hardware drivers can potentially conflict and installing multiple device drivers results in image bloat. It is often better to create different images for different hardware (not applicable if the end point is virtualized).
  • VDI for Wrong Reason: Organizations should do virtual desktops because there is a business reason to provide users with a Windows XP/Windows 7 desktop interface. Without a business reason, the virtual desktop solution will be seen as extravagant and costing too much money for no value.

That completes the current Top 10 list and honorable mention for virtual desktop mistakes. If you want, you can see the entire blog series via the Top 10 Virtual Desktop Mistakes link. If you prefer documents, then sign up for the XenDesktop Design Handbook where you will get the Top 10 list plus so much more.

Enjoy and good luck

Daniel – Lead Architect

I’ve spent the last month or so discussing the top 10 mistakes seen on desktop virtualization implementation so you can learn from other’s mistakes. I’ve discussed 9 different things so far and they were:

10.  Not calculating user bandwidth requirements

9.    Not considering the user profile

8.   Lack of Application Virtualization Strategy

7.  Improper Resource Allocation

6.  Protection from Anti-Virus

5. Managing the incoming storm

4. Not Optimizing the Desktop Image

3. Not using your Cache Wisely

2. Using VDI Defaults

And now it is time for the #1 thing that people mess up with desktop virtualization? (more…)