As organizations simplify desktop management activities through the use of desktop virtualization, creating a highly available architecture becomes ever more important. Historically, users were minimally impacted by desktop outages. In many situations, an outage typically impacted a single user, as one desktop device belonged to a single user. In a virtualized desktop operating model, there is the potential for an outage to impact hundreds or thousands of users if the environment is not designed appropriately.
This white paper focuses on the fault tolerant and high-availability options integrated with Citrix XenApp 6.5 as they align with three different focus areas:
- Layer 1 – Application Availability: Users should always be able to work with an available hosted shared desktop or application.
- Layer 2 – High Availability: Failures within a site should not impact desktop or application availability.
- Layer 3 – Business Continuity/Disaster Recovery: The loss of an entire site should not prevent users from accessing their desktops or applications.
By focusing on three distinct layers, an organization can feel confident in the operational availability of the architecture, even in the event of a catastrophic failure.
When delivered via XenDesktop or XenApp, a user’s desktop environment is built around four different layers:
- Operating System
In order to provide a user with the correct desktop, each one of the desktop layers must be highly-available. The focus of this whitepaper is on delivering high availability for published applications and hosted shared desktops. Information on delivering high availability for hosted virtual desktops can be found in the whitepaper.