ThinTech, specialists in the Delivery and Support of Virtual Desktop and to date have delivered over 100,000 desktops for some of the largest blue chip companies in the UK.
We are proud of our achievements and we know the benefits that virtual desktops brings to any size of company.
Our work was instrumental in bringing big savings many local authorities see: http://www.cbronline.com/news/enterprise-it/software/kent-councils-on-course-to-save-27m-sharing-services-4330097 or https://www.citrix.com/customers/medway-council-en.html or http://www.computerweekly.com/news/2240225809/East-Kent-Services-deploys-Citrix-virtual-desktop
The point here is not to brag, but emphasise how Desktop Virtualisation can transform any business and return a saving, but, only if it’s done right.
This guide is about giving you the building blocks in how tosuccessfully mplement solutions. You won’t get this information from any vendor, this is all ased on our experiences.Before we start, I have a simple mission statement, “I I’m o ensure every organisation is delighted with it’s virtual IT experience” Let me show you how we do it?
Understanding Desktop Virtualisation
It is important to understand that each vendor have their own way to describe desktop virtualisation solutions, Citrix with their Flexcast Model which currently has five different models available. Then you have VMWare calling their products the same as Citrix (Workspace) and then you have Quest and you have Teradici and 2X. All with their own marketing spin. It’s too much! Poor Customer is overloaded with choice!
The diagram below shows you all you need to know.
Virtual Desktop really only fits in to these four boxes, no matter what vendor you are considering.
- The desktop delivery options both VDI and Terminal Services Desktops
- Application availability (within the virtual desktop)
- Remote and offline capability
- Ensuring user profiles work across all solutions.
Desktop Choices – Use Cases
The following describe the use cases for the different desktops types to choose from based on our experience:
Server Session Desktop
A Server Session Desktop is typically Windows Server 2008 R2 running Citrix XenApp where many users log on to the same box but their windows appears to be the same as Windows 7, after a bit of tweaking.
The sorts of use case for this type of desktop would be:
- Someone who has no Administration access rights
- Someone who has applications assigned to them and they cannot install their own software.
- They do however want to work from any device
- They also may need remote access
- But need their desktop Highly Available
Virtual PC Desktop
A virtual PC is where you install the flavour of Windows on some form of Hypervisor and duplicate many time so that each user have their own full blown copy of Window to work from, this is called VDI.
VDI can be deployed as a pooled desktop where each user gets the same desktop or as a Private Desktop where give each user their own private desktop to suit their needs.
The use cases for each of these desktops are:
- For any user that would fit in the Server Session Desktop scenario but have unique application requirements that wont work on XenApp like digital whiteboards for teachers etc., you would give them a Pooled VDI Desktop
- For users that require full admins rights, maybe loads of RAM and want to install their own software I would give them a Private VDI Desktop
If we are honest with ourselves here, the majority of businesses I talk to say that pretty much most of their users would be quite happy with a Server Session Desktop providing it performs.
From experience we know that over 95% of users will sit quite happily in the Server Session Desktop and remaining 5% (usually IT Deptartments and really High end Cad\Cam Users) would use VDI.
What does this mean?
It is now possible virtualise 100% of your desktop estate in to your datacentre which opens up a number of performance improvements and allows you to look at desktop virtualisation as strategic solution and introduce services like BYOD and simplifies LAN network infrastructure because each desktop only needs around 100Kb\sec bandwidth when using Citrix
BYOD to me is all about locking down your core infrastructure and only allowing access to services via some security device and I prefer the Citrix Netscaler
If the only mechanism to access your virtual desktop estate is via a fully FIPS compliant SSL relay like the Netscaler then can treat the rest of your LAN being untrusted. Users can turn up with virus\trojan ridden devices that won’t get past the Netscalers so you can essentially say bring what you like to work and work from that if they like. That is what BYOD is to me.
User Profile Management
User profile management should never underestimated, If your serious about doing this you need a copy of our own profile management solution. We don’t charge for it and we call it TPMM. It works across operating systems and best of all it’s free. Think of it a an advantage in engaging with a specialist firm. Contact me for more details.
- Aim to get efficient use of hardware resources
- But Never over allocate Resources
- Never use shared resources for the desktop (Like the SAN)
- Guarantee your performance through design, Allocate 2vCPU’ 2GB RAM and 25 IOPS for each VDI Desktop and 16GB RAM, 4cCPU’s and 252 IOPS for each RDSH server which will run 35 sessions.
- Leverage XenServer as the Hypervisor (included in the license bundle)
- Produce a Desktop with a sub 30 second logon Because IOPS are under their greatest load at logon (up to 200 IOPS per session)
- Tweak Windows Server to look and feel identical as a VDI desktops
- Implement TPMM a Simple and robust User Personalisation
- Understand Resilience is built in to Citrix negating the need for any SAN
- All components that effect us need be engineered in to your solution examples being SQL & DHCP
Its starting to come together now, what does it mean?
Using the above mentioned methodology we have successfully, on many occasions, managed to get over two hundred Desktop! running on one mid range server.
This also means that we have significantly brought down the cost of using virtual desktops compared to a traditional PC replacement program, In fact it could be as low as 25% but typically comes in around 50% cheaper once you replace the PC’s with a cheap dumb terminal.
If we compare that to a pure VDI project which is typically more expensive than replacing PC’s both on a CAPEX and OPEX model you can see that Virtual Desktops does not have cost the earth.
A word of warning
Doing this is not easy, it does take time to get it right and getting it wrong will cause a whole bunch of bad press to vendor you choose and your IT Department.
I like to think of it being very similar to having a house built, you need your architects (TDA’s), you need your builders (Engineers) and you need you after-sales (Support). Follow this flow plan I have put together and you will see what I mean:
I hope you found this guide useful, if so please leave comments and remember all question are welcome: