The release of Citrix XenDesktop 5 has started with the release of the code to the web.  Given my company’s partnership with Citrix I’ve taken some looks at XenDesktop 5 a few times prior to the release but in the last few days I’ve really gotten to get more familiar with all portions of it.

There are A LOT of changes!  It’s almost frustrating to have to re-learn so much…but I guess this is the career I chose.  What are the biggest changes that make the biggest difference to administrators of these environments?

• Improved Desktop provisioning process
• Desktop Director and Desktop Studio

Let’s start with the first bullet: Desktop Provisioning

In XenDesktop 4 for desktop image management we use Citrix Provisioning Server (PVS).  Citrix Provisioning Server is a very slick product, acquired a few years ago from a company named Ardence, it allows for the streaming of a captured image from Provisioning Server to a physical or virtual machine.

The process goes like this:  Build a gold image on physical or virtual machine, capture the image to Citrix PVS, boot physical or virtual machines via a bootstrap file (can be done via PXE or CD-Rom media), the physical or virtual machines see the hosted image on Citrix Provisioning Server as essentially local disk and off you go.  A single read-only image can be shared across hundreds to thousands of machines.  The disk writes to are then re-directed (in most cases) to a local virtual or physical disk cache file.  (no SAN needed!)

In the education sector where large computer labs exist this product allows us centrally manage as few as 1 image for all of the physical machines while still allowing cpu/memory/video processing to be done on the local physical machine.  A single Citrix Provisioning Server with local disk can centrally manage hundreds or thousands of machines…because the processing is all done locally on the physical machine…try doing that with a hosted desktops!  The best part of this is that you continue to use the physical cpu, memory, disk, video on the physical machines and don’t have to build out a huge VDI infrastructure…and those applications like CAD aren’t a problem because we’re still using physical resources on the PC!

Now the often overlooked part of Citrix Provisioning Server has been how it manages the identity of the images it delivers.  When images are delivered to physical or virtual machines Citrix Provisioning Server inserts identity information into the boot process (computer name, syncs machine account with Active Directory machine account) so that you don’t have to quick-prep or sysprep new machines…allowing you to VERY quickly deliver hundreds or thousands of new machines.

In XenDesktop 5 Citrix has modified how they use Citrix Provisioning Server.  First of all you no longer need to install Citrix Provisioning Server if you are deploying hosted virtual desktops.  In a hosted virtual desktop model you now build a “gold” virtual machine, take a snapshot of that VM, then create or update a machine catalog to point to that new snapshot and Citrix takes care of the rest!  Creating Machine Catalogs.  Your virtual machines use that point in time snapshot of your gold image for their disk reads and all writes (changes) go to a virtual disk attached to the VM (think vmware linked clone’ish).  So how does this differ from VMware you might be wondering?  Well in a VMware environment you have to quick-prep or sysprep all of these new virtual machines when they are provisioned.  In Citrix XenDesktop 5 an identity disk is created by the Machine Identity Service (using technology from Citrix Provisioning Server) these new machines “magically” come up with their unique identities tied to their Active Directory machine accounts!  What does this mean for the administrator of this system?  Well basically new pools of virtual desktops can be created with hundreds to thousands of machines pretty much on demand when they are needed because there is no quick-prep or sysprep involved…and because we’re not depending on Citrix Provisioning Server(s) high availability is GREATLY simplified.

If you never used Citrix XenDesktop 4 most of this history doesn’t matter to you…if you have…XenDesktop 5 is MUCH faster and easier to deliver hosted virtual machines.  If you require delivery of an image out to your physical machines as we discussed, Citrix Provisioning Server would then be installed and Desktop Studio and Desktop Director bring visibility into that environment.

That’s it for now, I’ll write about Desktop Director and Desktop Studio that are part of Citrix XenDesktop 5 in my next post.