Greg Porter, MCITP: EA, Cal Poly October 17, 2010

What is a desktop virtualization?  Depends on the marketing droid you are talking to – there’s a lot of hype.  Desktop virtualization… separates a… desktop environment from a physical machine using a client–server model of computing. The model stores the resulting "virtualized" desktop on a remote central server… thus, when users work from their remote desktop client, all of the programs, applications, processes, and data used are kept and run centrally. (Wikipedia)

This isn’t new…  This was the ORIGINAL model of computing - a “terminal” (character based display device) attached to a remote server  X Windows (Unix) based solutions for doing this have been around for 20+ years

Why the hype now?  Desktops are out of control, users load and run whatever they like on “their” workstations Hard to support, no standard software Hard to manage configuration, no telling what’s installed Risk of data loss, company data not safe  Businesses need to “prove” compliance with IT security policies

Shared Services  Many users share one machine A user can “run away” with RAM or CPU Different users may need different apps that conflict with each other  Can be relatively simple to deploy  Sun Global Desktop, Citrix XenApp, Windows Terminal Services

Shared Services (a la Terminal Services, XenApp)

Desktop Virtualization  Similar to shared services but: Each user gets “their own” virtual machine Machines can be spawned on demand from a golden image Desktop controller server manages user connections, VM power states, load balancing Users CAN share a machine if appropriate  Citrix XenDesktop, VMware View

Desktop Virtualization

Production Example – Vmware View

Achilles has a heel  All of these schemes require a display device – you need a desktop to see your desktop  Business would like to reuse their existing PC’s until they die – repurposed as thin clients If you reuse PC’s, now you have to manage the desktop machines you already have PLUS the virtualization infrastructure  End users in general don’t like the idea of thin clients – you are taking “their” machine away

You could re-use your PC’s  Make and deploy a stripped down OS image Bare minimum Windows + proper client software (ICA client for Citrix, View client for VMware)  Defer replacement for now, save a little money in the short term  Double the work, you have to manage the real workstations, plus the virtual workstations

You could buy actual thin clients  A couple of hundred dollars a piece, not that much cheaper than an entry level workstation  Run their OS from firmware, no moving parts  Most have some firmware update management scheme  Easy to manage than repurposed PC’s  Get the “right” one for your solution Make sure the ones you buy natively connect to your solution. ICA clients for Citrix, View clients for VMware, etc.

Lessons Learned  Vendors wildly overstate the savings  Dramatically increases complexity on the server side, especially if business has little existing experience with virtualization  End users typically hate thin clients To be accepted, the “new” solution has to be dramatically better than the old desktops Someone suggested stuffing the thin clients into an empty desktop case…  Once they use it, end users *REALLY* like having their desktops available from anywhere  They also *REALLY* like persistent state, where they can disconnect, then reconnect, and continue where they left off (a la Session Broker, etc.)

Here’s something truly new – On Demand Desktop Streaming  Originally made by Ardence, licensed by Dell (ODDS), now part of Citrix XenDesktop (Citrix Provisioning Server)  Boot many PC’s from one central image  PC’s don’t need a hard drive  Can display a menu of boot images to pick from - Linux, Windows, etc.  You don’t need a desktop to see a desktop  Ardence demonstration Ardence demonstration  Head to head with SATA at Univ. of Neb. Head to head with SATA at Univ. of Neb © 2010 by Gregory L. Porter, This work is licensed under the Creative Commons Attribution-Noncommercial-Share Alike 3.0 Unported License. To view a copy of this license, visit or send a letter to Creative Commons, 171 Second Street, Suite 300, San Francisco, California, 94105, USA