According to Citrix, the number one mistake people make when deploying VDI is not sizing their storage properly for performance. However, calculating a target IOPS for your environment is far from easy and you really need to understand VDI, its unique workloads, and your storage subsystem. There are many blogs about this topic, so I'm not going to rehash them. But I will provide a good list of what I think is required reading if you are going to deploy VDI in production on any scale, above a few dozen VMs.
Great links to check out:
VDI Calculator
Finding a Better Way to Estimate IOPS for VDI
Windows 7 IOPS Deep Dive
Virtual Desktop Resource Allocation
Improper Storage Design for Virtual Desktops is a Killer
Deciding on Local or Shared Storage for your Desktop Virtualization Solution
Estimate IOPS for Virtual Desktops
Data Storage for VDI - Part 2 - Disk Latencies
Data Storage for VDI - Part 3 - Read and Write Caching
Data Storage for VDI - Part 4 - Impact of RAID on Performance
Video: Storage Infrastructure Design Guidelines
HP XenDesktop 1,000 User Reference Architecture
RAID options with Desktop Virtualization
Local or Shared Storage - that is the question
Does Cache Trump IOPS
VDI Storage Calculator Spreadsheet
VDI & Storage - Deep Impact
VDI IOPS Calculator
Interesting VDI storage products:
xiotech Hybrid ISE
WhipTail
Atlantis Computing
IntelliCache and the IOPS Problem
Below is a sample calculation for 2,000 users using a moderate IOPS profile. According to these calculations for RAID-1 your disk array would need 273 15K disks!
Enjoy!

Another new vendor that delivers optimized storage in virtualized environments you may want to check out is Virsto Software (http://virsto.com/solutions/virtual-desktop-infrastructure-vdi)
ReplyDeleteThey have a unique logging architecture and install directly into the hypervisor, sequentializing all of the random I/O from the virtual desktops and delivering improved performance to the end user, then asynchronously destaging to a primary virtual storage pool that supports tiering.
Reduces cost of storage per desktop up to 70% and very fast provisioning of hundreds of images.