Citrix XenDesktop
Citrix XenDesktop 7.6 is the latest incarnation of Citrix's Virtual Desktop Infrastructure (VDI) product, which builds ease of installation, ease of configuration and enhanced scalability on the previous version.
XenDesktop provides the ability to dynamically create virtual desktops (created in a central pool) which can then be accessed directly by users from their computers using remote technologies provided in conjunction with the Citrix Receiver.
The key components in this solution are:
• StoreFront
• Controller
• Hypervisor
• SQL Database
StoreFront
The StoreFront provides the entry point for the user to initiate a connection to a virtual desktop. The StoreFront is a portal which can be tailored to suit corporate tastes and can provide access to other Citrix based services.
Hypervisor
Citrix XenServer, VMware vSphere (ESX) and Microsoft Hyper-V can provide the hypervisor technology for virtual desktops which are created in a data centre and then accessed remotely by users. XenServer is based on virtualisation technology acquired from Xen and redeveloped by Citrix.
XenDesktop uses an open architecture allowing it to be used with different hypervisors such as Microsoft (Hyper-V), Citrix XenServer and VMware (ESX).
The hypervisor provides a pool of desktops known as the 'Hypervisor Pool', which are made available remotely to end users.
Controller
The controller (previously known as the Desktop Delivery Controller) brokers user access to desktops through the integration with existing authentication services such as Microsoft's Active Directory.
The controller monitors the connection state between the users and their desktops and can be configured to select particular desktops (dedicated) or to use a 'pool' of similar desktops.
The controller also includes the 'Machine Creation Service', a cut down version of Provisioning Services (PVS) which allows provisioning of virtual machines to hypervisor pools. The full version of Provisioning Services allows provisioning to physical desktops aswell as hypervisor pools in comparison.
XenDesktop Site
The term 'Site' replaces the term 'Farm' which Citrix used with previous versions and with their presentation server (XenApp) product. The site concept has some similarity with the Active Directory Site concept, where the connectivity within a site, dictates the boundaries of a site.
A XenDesktop site contains the hypervisor pool, which contains the virtual desktops which are accessed remotely by end users.
Desktop Studio
Desktop Studio provides the management interface which allows for the configuration and management of XenDesktop deployments. Desktop Studio includes various wizards which can guide administrators through the process of setting up a XenDesktop environment, creating desktops and assigning desktops to users.
Desktop Director
Enables 1st Line (level-1) and 2nd Line (level-2) IT Support staff to monitor XenDesktop deployments and perform day-to-day maintenance tasks. Support staff can also view and interact with a user's session, using Microsoft Remote Assistance, to troubleshoot problems.Citrix online plug-in The Citrix online plug-in is installed on user devices and enables direct ICA connections from user devices to virtual desktops.
XenDesktop Licensing
XenDesktop is licensed in either per user or per device mode for all Enterprise, Platinum and VDI editions, with the VDI edition including an additional concurrent user (CCU) licensing option. There is also an Express edition designed for technology professionals to quickly deploy a 'Proof of Concept' (POC) environment to evaluate XenDesktop. The Express edition is limited to 10 licenses.
SQL Database
A SQL Database is required to host information from the XenDesktop site. For resilience, it is recommended some form of clustering such as mirroring is used to ensure the availability of the database.
