Using SSD for VDI
Today I read an excellent blog post on VDI performance by Ron Ogelsby on the Unidesk site (Unidesk are a provider of desktop layering software for VDI). In it he contrasts various approaches to SSD usage in a VDI environment. He falls on the side of SSD in the array and concludes “The answer you want to hear is that they are carving out a portion of the SSD for the write operations”.
Ron is absolutely correct. VDI is a unique workload with a changing I/O pattern. Many people are focused on SSD as read cache to handle boot storms but are not considering that the general daily VDI workload is heavily orientated to random writes.
This is why at Starboard Storage our SSD Accelerator is designed with dedicated read and write cache SSD resources. (See diagram below). Write-back cache is mirrored for data protection but read cache does not need to be as it is simply a copy of data already on disk.
Using this architecture we are able to handle mixed workloads exceptionally well and VDI is the ultimate mixed workload.
So if you are looking for a solution using SSD for VDI make sure you really understand what the vendor is doing for write caching as well as read caching.
Read more on Starboard Unified Hybrid Storage here www.starboardstorage.com
You can read Ron Ogelsby’s article on the Unidesk site here :-