VDI lately became a big topic that everyone is talking about and project are up in the market for grabs for migrating 1000,3000,10000 and even 15000 PC units into a VDI ready solution, personally having implemented and consulted this technology before I have a few points I want to highlight to anyone who is in the process of considering this technology.
1. Study your business. As an IT manager/administrator you need to really and carefully study your infrastructure and identify what kind of loads you are having. As an exercise I generally use an excel sheet and break down my users by categories where CAT A will be the normal officer users(excel, word, outlook), CAT B will be the more intensive users (matlab, autocad, GIS app) and so on. After doing that you can use various tool even primitive ones like task manager in windows to identify what kind of load its consuming from your local PC, normally it would be around 60-70% of you Current Ram and no more than 10% of your CPU’s capabilities.
2. Manage your expectation. If you are looking for a device that do exactly what a PC is doing than you are shopping in the wrong place. You need to keep an open mind on the capabilities of a VDI solution. Later on we will discuss the different types of VDI’s and how they are differentiated from each other. As a general standard if up to 70% are low end users (office, call center, browsing) than VDI would be a good feasible approach but don’t try to cramp the extra 30% into that play. A very heavy visual intensive user is better off with a PC on his own.
3. Choose your platform. In today’s market you have two choices of going about this thing. Either you use a full software based VDI where your virtualize a processing/storage pool and project it to existing PC’s and by that having your PC act like a terminal and get his session and resources from the pool or you can go full fledge and invest in a thin client/zero client dummy devices to replace your PC’s and act as your terminals. A lot of customers use a hybrid of both where for their new development they buy thin clients while utilizing the existing PC as a terminal until it get depreciated from the financial department thus become feasible to replace it.
4. Do a proper sizing. Four aspects are usually involved in the sizing activity.
a. Server infrastructure sizing- this is where all of your VDI sessions will work and play as well your brokers or gatekeepers between your Clients and your virtual sessions. The sizing of these servers need to come from finding the right sizing formula (i.e: each Xeon Core can hold up to 10 users with 1.5GB RAM for win7 and 100GB of Disk), you need also to make sure that you have a lot of PCI Nics going out of the boxes since these kind of solution draw a lot of I/O bandwidth and speed so you need to concentrate on that.
b. Storage infrastructure sizing- you will need a good SATA box with proper dual controller with a decent number of RAM(24 GB ) and a read flash card if possible. You will also need as much of PCI Nics going out of the box as well. Deduping, compression and Raid-Dp is a must in these scenarios to tackle the bottle necks you might face on your storage array.
c. Network infrastructure sizing- Make sure that all of your connectivity from all sides is redundant, always remember that in project like these, the entire setup is one big single point of failure unless you do a huge investment an duplicate the whole thing so get good switches with sufficient port numbers and if possible create a 10gbps inter structure connectivity between server and storage since it will enhance your solution.
d. HA sizing- always do an HA sizing and planning specially on your server side for example if 200 users can run on two servers with a 60% utilization of each, this is not HA since as soon the first server goes down the second one will not be able to handle the load and will probably crash as well, always have an N+1 topology in mind when you size.
5. Choose your platform – in today’s market there are 4 top VDI players with citrix Xen desktop on top followed by vmware, Microsoft and Oracle virtual box. In concept all four perform in the same manner however they do compete mainly on the GPU acceleration, compression and security. I would advise testing all four of them to see what suits your taste where you need to weigh the free license of Microsoft and oracle OVM versus the capabilities of citrix and vmware and that is a decision you need to take as per your running app and environment.
6. Choose your client – virtually everybody today have a thin/zero client device in their portfolio be it Dell, HP, IBM, Oracle, fujitsu and even hawaeii have a 75$ linux based device that performed surprisingly well in our benchmark. When this originally started, all client technologies were dummy clients for basic operations, as IT and business evolved there was a demand for the client to do more and more up to verge of demanding to run graphical intensive applications thus nowadays clients with a GPU processing unit, a small ram chip and a built in OS is very popular and in demand but relatively a bit more expensive to purchase and maintain as an overhead. One of the leading GPU enabled Client provider would have to be Fujitsu while Oralce/Sun still preside the zero client business line as the leader in that field and the most easy on the eye design with their new MAC look sunray 3i all in one 24 inch machine.
At the end of it, it all comes down on how you are planning to use the VDI technology. Today you can run your VDI on your PAD, mobile, PC’s, thin clients and even browsers running java tomorrow sky is the limit for this technology since it is seen as the user interface to the Cloud and an inseparable part of the modern structure.