Andy Baker wrote a good post on the Citrix blogs about the Hardware and Storage calculator.
During your desktop transformation project, you’ll need to estimate hardware and storage requirements so that project costs can be calculated and the infrastructure can be ordered. To provide an accurate estimate you’ll need to consider many different factors – including virtual desktops per host, virtual desktops per site, desktops per controller, users per XenApp Server, XenApp Servers per host, users per farm, hosts per resource pool, IOPS per VM and many others.
It’s a lot to consider – so where’s a good place to start?
At Citrix Consulting, we’ve had a lot of experience estimating hardware and storage requirements for desktop transformation projects, and we want you to benefit from that knowledge so that you’re not starting from scratch. I’ve created a spreadsheet that estimates the number of virtualization hosts and storage required based on a number of key inputs:
Virtual Desktop Spec: Processor, storage and disk requirements for light, normal and heavy users.
Virtual Hard Disks: Number and size of virtual hard disks required.
User Segmentation: Details of the user groups identified during segmentation process, including number of users, performance requirements and chosen FlexCast models.
Hardware: You can allocate different hardware specs (cores, RAM and redundancy) to the virtualization hosts supporting the XenApp Servers, XenDesktop virtual desktops and infrastructure servers if you wish.
The spreadsheet will use these inputs to estimate how many infrastructure servers are required – Web Interface, XenDesktop controllers, XenApp servers, XML Brokers, Desktop Director Servers, Provisioning servers and License Servers (which you can adjust if necessary).
It will then use all of this information provided to calculate how many virtualization hosts, physical servers and virtual appliances are required as well as the storage space and IOPS.
I’ve tried to simplify the spreadsheet by making a number of assumptions such as redundancy requirements, hypervisor overhead and streams per Provisioning server. All of these items can be adjusted within the Advanced tab. You should review these assumptions to make sure that they make sense in your environment – you can change them if necessary.
You can download the spreadsheet from the Desktop Transformation Accelerator site – http://www.citrix.com/dtaccelerator. After you’ve created a project, navigate to Design > Design the platform layer > Calculate your hardware needs. White cells require you to enter or review information, green cells are automatically calculated and yellow cells provide guidance. I’ve pre-populated the spreadsheet with some example information to steer you in the right direction.