White Papers

BP1018 Sizing and Best Practices for Citrix XenDesktop with Dell EqualLogic Storage 16
The typical industry standard latency limit for storage disk I/O is around 20 ms. Maintaining this limit
will ensure good user application response times when there are no other bottlenecks at the
infrastructure layer
4.4.2 System resource utilization on the hypervisor infrastructure
The primary focus of our testing was storage, and we ensured that no other component in the VDI
stack became a bottleneck while conducting these storage characterization tests. We used the
following metrics at the hypervisor infrastructure layer to ensure solution consistency:
• CPU utilization on any ESXi servers not reaching 95% at any point in time
• Minimal or no memory ballooning on ESXi servers
• Total network bandwidth utilization not to exceed 90%
• Storage network retransmission less than 0.5%
4.4.3 Virtual desktop user experience
VDI configurations involve many components at different layers – application, hypervisor, server,
storage and network. As a result, multiple metrics need to be monitored at different layers to ensure
that the environment is healthy and performing appropriately for users. Liquidware Labs Stratusphere
UX was used to assess the performance of each desktop (application level).
We used the following user experience criteria:
- At least 90% of the virtual desktops are in the ‘Good” performance category.
- No virtual desktop should be in the ‘Poor” performance category.
The various criteria used to determine user experience and also other detailed information about how
this metric is calculated using the Stratusphere tool is available in the following document:
http://www.liquidwarelabs.com/docs/VDI%20Fit%20and%20VDI%20UX%20White%20Paper.pdf