To get our virtual desktop infrastructure rolling review started, we took VMware's View 3 (follow-up to VDI Version 2.1) for a spin in our Boston labs. If you're not quite getting what you expected out of your terminal services environment, View 3 might cure what ails you.

Ask Citrix or Microsoft Terminal Services administrators what their biggest pain points are, and the most common answer will be issues related to application deployment/compatibility, printing, and session management. Some admins even have to mix in some application virtualization via Microsoft SoftGrid in order to keep those legacy applications humming along. And what if one of your Citrix users needs to install a custom application? Better hope that custom app doesn't take down the Citrix server.

Forward-thinking IT managers are increasingly turning to virtualized desktops. If your user needs to install a custom app, no problem: The virtual desktop acts just like a fat client computer. If your user blows up his virtual desktop with spyware, just blow up the VM and re-create it instantly with a virtual template. Although terminal services is still the best solution for serving individual apps in a WAN-friendly way, VDI is quickly becoming the best solution for IT shops unhappy with the limitations of a full Citrix or Microsoft Terminal Services desktop session

VDI And The Law
Our real-world scenario centers on a fictional legal startup called Bits & Bytes Legal Services LLC that's building a VDI-based desktop computing environment from scratch. B&B's decision to implement VDI was driven by several factors, the most important of which was security. The centralization of the operating system, along with all critical business data, ensures that damage is minimized in the event of a thin client or laptop theft.

In addition, B&B wants to ensure users can customize their desktop computing environment as though it were a full client. Finally, B&B wants the ability to convert VMware's VMDK (Virtual Machine Disk Format) file format to store virtual desktop templates to Symantec Ghost images. That way, the VDI environment can act like a master desktop image repository, where fat client images can be deployed ad hoc if need be.

B&B employs 100 attorneys and paralegals, with 25 workers in its Boston headquarters, and 75 distributed among spoke sites in Silicon Valley, Dallas, and Washington, D.C. The Silicon Valley office is connected to the Boston HQ with two bonded T1s (two T1s together to obtain an aggregate bandwidth of 3 Mbps), the Washington office connects via a single T1, and the Dallas office is connected with a 1.5-Mbps-down, 512-Kbps-up DSL circuit, and network latency could potentially impact quality of service. Before plowing ahead with an investment in VDI, B&B must determine how the WAN would affect its ability to serve out virtual desktops at an acceptable performance level.

For this Rolling Review scenario, VMware provided a VDI system that included a back-end ESX 3.5 Server to store virtual desktops, a front-end server running the Virtual Desktop Manager connection broker software, and a virtual infrastructure environment for managing VMs and back-end ESX servers. All components can be deployed within VMs on a single physical box, but because the VDM requires a 2-GHz Pentium 4 CPU, along with 2 GB of RAM, VMware recommended physically separating the VDM connection broker from the back-end ESX server. More important, the VDM connection broker requires Windows 2003 Server, and VMware's Virtual Center enterprise virtualization management tool can't be installed on the same box.

The implementation may sound daunting, but it was extremely simple to deploy. ESX Server installation is fully automated, and the VDM connection broker software installed in minutes on our front-end Windows 2003 Server build. The only major installation decision to make was whether or not the front-end VDM would serve in standalone or redundant capacity. After building our VMs within VirtualCenter, the last step included logging in to the Web-enabled VDM management GUI, applying our evaluation license, and adding the virtual desktops we wanted to serve out to clients.

Through the VDM manager, administrators can tie individual virtual desktops to a specific user through his or her Active Directory user account credentials credentials. A pool of virtual desktops can be provisioned to a group of employees, in persistent or nonpersistent mode. In nonpersistent mode, all customizations to the virtual desktop are lost when the virtual desktop is closed. In persistent mode, all state information is saved when the virtual desktop is shut down. Clients can access their virtual desktops via single sign-on through the VDM client software, or via a browser based Web client.