FalconStor VDI Solution: Economics And Performance

On August 24th, FalconStor announced their new NSS SAN Accelerator for VMware Virtual Desk Top Environments, and Network Computing covered it here. FalconStor briefed me on this solution prior to their announcement, and I was impressed with it. FalconStor has been developing some highly creative storage solutions, and I thought it time to take a closer look at this one and spend some time talking with someone who is using it. To say that I was even more impressed with the FalconStor solution after my conversation is an understatement.

Founded in 2000, FalconStor has consistently provided storage solutions and was one of the first companies to provide storage virtualization capabilities along with being an OEM vendor for a number of widely accepted backup and recovery products such as EMC's Data Library series. It is encouraging to see the company provide solutions for the virtual machine space and especially for the virtual desktop infrastructure (VDI).

After being briefed on the new VDI solution, I took some time to digest the technology and then spoke with Sam Lee, senior solutions architect, Data Centers, at Force 3, who provides enterprise data center solutions for the Federal government and commercial environments. Lee was an early adopter of VDI solutions, and he found that storage I/O performance not as good as anticipated as well as being a root cause of boot and sign-in problems. He learned a lot about desktop behavior. "Early on we had little understanding about desk-top behavior. I believe we all underestimated what desk-top virtualization really means," Lee explained.  

The thought process was that desktop consolidation would be similar to server consolidation, perhaps a five to one ratio. In actual implementation, Force 3 found that a 50 to one ratio was more realistic in order to provide attractive economics; however the storage I/O latency hovered around a crippling 70 to 80ms range. Understandably, the early VDI solutions were not performance-friendly, and in an effort to reduce latency by adding more storage devices, the total storage cost was unacceptable and out of reach.

After Lee's initial experience, he went on a year-long search for a more practical solution.  During this time, he learned even more about the desktop environment. "All the desktop data is valuable. Nothing gets blown away. For VDI, it's more about data value tiering as opposed to performance tiering, but we still need high performance in the storage I/O," said Lee.  The data-value tiering concept is the reverse of what we commonly see in the storage industry; performance tiering is more commonplace.  Eventually, while Lee was working on a telecommuting solution with CISCO and FalconStor (for high availability), he learned of FalconStor's NSS SAN Accelerator for VMware virtual desktop environments. After a number of test-runs with the FalconStor solution in a VDI environment, his analogy was that the storage I/O performance "was similar to having Fusion I/O solid state devices in the server. It was really fast. The storage I/O results realized with the FalconStor solution were around 70,000 IOPs with a 50/50 read-to-write ratio at a 4K block size on 4GB fixed block LUNs," Lee stated.

Now Lee is testing a VDI environment with the FalconStor NSS SAN Accelerator with SSD that supplies approximately 4GB's per user, linked clones, regular refreshes (daily, weekly, monthly) with user persistent disks. He is testing 320 virtual machines and sees minimal impact on Windows boot times and is continuing to see low latency for storage I/O. He believes he can now provide the data-value tiering and storage economics that make sense for an overall enterprise class VDI solution. Lee says, "The FalconStor ability to automatically move data from disk to SSD and back to disk at critical time periods is a huge value and also offers the storage economics needed." Sam Lee has leveraged his experience and developed a reference architecture white paper which can be found here at the Force 3 website.

The deployment of virtual machine environments continues to climb at an explosive rate and virtualizing the desktop makes sense if the economics are attractive and desktop users remain ecstatic with their overall experience. Solutions such as the FalconStor NSS SAN Accelerator for VMware View help advance IT automation and reduce overall costs.

Are you considering implementing a virtual desktop environment? If so, I would like to hear from you and understand your experiences to date and your plans for implementation.  Are you considering the use of SSD?  Has storage pricing been a prohibitive factor?