Selecting a Microsoft Azure VM machine instance type can be confusing and costly. This article aims to clarify the options that Citrix XenDesktop and Workplace Cloud Apps and Desktops presents and their implications.

Background

When hosting VMs in the cloud, the cloud providers offer customers a wide range of VM size and performance options to meet the needs of customers’ workloads. When creating a new machine catalog, consider the following items when selecting a virtual machine size:

• Options presented by Studio

• Cost and performance of the VM instance type

Options presented by Studio

Studio presents all of the VM instance options that Microsoft Azure makes available in a selected region. So, you will need to understand the nature of your applications and the resources they will require, such as CPU, memory, or I/O, when selecting an appropriate machine size.

Cost and performance of VM instance types

Microsoft Azure provides many choices at different price and performance points. Refer to the following Microsoft links to better understand the pricing and performance options:

• MSDN – Virtual Machine and Cloud Service Sizes for Azure

• Virtual Machine Pricing

VMs prefixed with “Basic” use a basic disk limited primarily by the level of IOPS supported by Microsoft Azure, which is 300 IOPS. Citrix does not recommended this tier for Citrix Desktop OS (VDI) or Citrix Server OS (RDSH) workloads.

For a detailed comparison of Azure VM instance types, refer to the whitepaper “Deploying XenApp 7.5 on Microsoft Azure cloud” at http://www.citrixandmicrosoft.com/Documents/Citrix%20XenApp%207.5%20on%20Azure.pdf.

In summary, for Citrix VDI or Citrix RDSH workloads, testing results using LoginVSI against its medium workload found that Medium (A2) and Large (A3) instance types offered the best price-to-performance ratio. Medium (A2) and Large (A3 or A5) instance types represent the best cost-to-performance for evaluating workloads. Citrix does not recommend using smaller instance types. More capable VM series may offer your applications or users the performance and usability they demand. However, you should baseline against one of these three types to determine if the higher cost of a more capable VM instance type is going to be of any value.