At this past TechEd 2011 in Atlanta I met with Gregg Holzrichter, the VP of marketing for Virsto. Virsto makes Virsto VSI for Hyper-V which is storage virtualization software for Microsoft’s Hyper-V virtualization platform. Virsto claims that it can achieve a 3X improvement in Hyper-V storage performance and can decrease storage by up to 90% in some VDI scenarios.
Vistso works by optimizing the I/O that the Hyper-V host writes to disk. Virsto VSI for Hyper-V is implemented as file system filter driver and it intercepts file system I/O operations. Individually all of the different VM’s perform a large amount of random writes to storage. Virsto captures all of those writes in a transaction log file and then writes them to disk sequentially significantly enhancing the I/Os per second that the host can perform.
Virsto is installed to the Hyper-V parent partition and it implements a new VHD type called a vDisk. Virsto claims that their vDisk outperforms native Hyper-V fixed disk implementations while simultaneously offing the space saving advantages of dynamic disks. Using this new vDisk VHD is completely optional. If you do choose to implement it then the Hyper-V VM that uses it will get the performance and storage advantages provided by Virsto VSI for Hyper-V. Virsto VSI is compatible with the Hyper-V Manager, Microsoft System Center as well as Windows Volume Shadow Copy Service and Failover Clustering.
Virsto VSI for Hyper-V is licensed at $2800 per host. You can find out more about Virsto and their storage virtualization products at: http://www.virsto.com/