Reference Architecture Design for Implementation of Citrix XenDesktop on Cisco Unified Computing System, Citrix XenServer, and NetApp Storage
The Citrix XenDesktop on the Citrix XenServer FlexCast models Hosted VDI and Hosted Shared running on Cisco UCS B-Series Blade Servers were successfully validated.
The Cisco UCS B250 M2 Extended Memory Blade Servers offer an optimal memory configuration that allows virtual desktop hosting servers to use the full CPU capabilities of the servers. The 192 GB of memory allowed a high density of desktop sessions per Cisco UCS B250 M2 Extended Memory Blade Servers while offering 1.5 GB of memory to be allocated per desktop-based virtual machine. We were able to scale to 110 windows 7 desktops while running knowledge worker load.
The validated environment consisted of only virtual machines hosted by Citrix XenServer. All the virtual desktop and supporting infrastructure components including Active Directory, Citrix Provisioning Server, and the Citrix XenDesktop Desktop Delivery Controllers were hosted in a virtual machine environment on Citrix XenServer 5.6.
Linear scalability when going from 1 server to 8 servers to 16 servers; the results being with 1 server we had 110 desktops running and with 16 we got 1760 desktops with the same response time.
Rapid provisioning with Cisco UCS Manager makes it easy for scaling from 1 chassis to 2 and so on.
The 10G unified fabric story gets a stronger validation as we see tremendous performance with respect to user response times during the load test.
With proper backend storage scaling we can scale out Cisco UCS domain from 4 chassis and beyond without making any changes to the proposed Reference architecture.
Desktop virtual machine Boot-ups or Logon Storms (from rapid concurrent or simultaneous user logons) have the largest scalability impact to this solution as well as VDI environments in general.