Compaq ML350 Citrix XenDesktop architecture and implementation on ProLiant ser - Page 2

Abstract The goal of this integration note is to describe Citrix XenDesktop technology, architecture, and implementation on ProLiant servers. The audience is both internal and external customers. What is Citrix XenDesktop? In a traditional PC workstation environment, users have a virtually unlimited ability to install or remove software. IT departments often use products, such as terminal servers, that provide a stable but locked down desktop environment to the user. Desktop virtualization involves server-based computing that gives system administrators the ability to centrally manage and host desktop virtual machines in the data center while giving end users a full PC desktop experience. Desktop virtualization provides many of the advantages of a terminal server, but can provide users added flexibility, such as the ability to install and configure applications, as well as the ability to access virtual desktops from other locations. Virtual desktops are dynamically assembled on demand, providing users with new, personalized desktops each time they log on, as well as high-speed network responsiveness. Citrix XenDesktop allows both medium and large businesses to take advantage of the benefits and cost savings of virtualization. XenDesktop delivers Microsoft Windows XP or Vista virtual desktops to users on a wide variety of endpoints, which are devices such as thin clients that provide users with a desktop computing environment. On the desktop side, XenDesktop integrates with Citrix XenServer to provide desktop virtualization, which enables many Windows-based desktop operating systems (such as Windows XP or Vista) to be centrally hosted in the data center and delivered to users anywhere. HP provides an integrated version of the Citrix XenServer hypervisor (virtualization layer) for HP ProLiant servers. XenServer can be used as a stand-alone virtual machine server or upgraded and combined with other ProLiant servers running the HP integrated Citrix XenServer to create pools of servers sharing storage and enabling live migration of virtual machines between servers. On the server side, XenServer provides server virtualization, enabling one hardware device to host multiple server operating systems (such as Windows Server 2003) to provide better server utilization and data center consolidation. Virtual Desktops Virtual desktops are desktop operating systems (for example, Windows XP) running on a virtual machine (VM) that, in turn, runs on XenServer (Figure 1). The XenDesktop solution also uses virtual desktop agents, software running in a virtual machine (VM) that enables the operating system to make its desktop available to another computer (or endpoint device). The agents communicate with XenDesktop and control the start/stop of the virtual desktops as defined for the idle pool (the group of available virtual desktops). When a user logs out, XenDesktop communicates directly with the XenServer and requests that the agent restart the virtual machine so the virtual desktop will be available for a new user. 2