I am currently in Beijing halfway through a five city roadshow to present and listen to EMC’s technical pre-sales team. One of my roles in this traveling show is to talk about vSphere 5, and all of the great things EMC is doing to make it even better for customers. A big part of my talk is centered around the new vStorage API for Storage Awareness, or VASA. I think this new API is going to provide value far beyond what most people realize.
This new API allows VASA-enabled arrays (such as EMC’s VMAX and VNX) to expose storage architecture details to vSphere. Instead of only seeing a block or file device with some amount of capacity, VASA allows vCenter to know about replication, RAID, compression, deduplication, and other storage features. With this new information VMware administrators can create storage profiles that map to volumes. Virtual machines can then be assigned storage by policy, and not just the availability of space.
This is a subtle change in the way applications are mapped to storage with a potentially very large impact to the efficiency of virtual environments. If you think about it, until the creation of VASA, administrators were forced to manually enforce the mapping between applications and storage. Mistakes in this mapping could result in critical applications residing on unprotected storage. The other mistake is when low priority applications find themselves hosted on very expensive storage backed by high performance media, replicated, and on the nicest arrays in the environment. The first mistake can mean data is lost in a failure. The second mistake means much more is being spent on storage than needed.
The promise of VASA is that applications will always be properly mapped to their ideal storage. This introduce a new mechanism for application deployment, where applications are deployed to storage based on policy which is enforced by vSphere. Policy-based deployment will be more efficient and suffer fewer mistakes. The potential value to customers is very large.
My expectation is that VASA will not immediately resonate among storage companies’ pre-sales teams the way VAAI did. And without storage companies pushing it, customers may not realize the incredible power of this new API. VAAI is simple and sexy and its value can be seen in a five minute demonstration, as Chad showed when vSphere 4.1 launched.
But VASA is subtle. How do you demonstrate the value of guaranteeing a print server does not end up on solid state disks? How do you quantify the cost of lost data from a mission critical application that was placed on unprotected storage? Because these questions are not easy to answer, I fear the world will not realize the might of VASA. But, day-by-day VASA will uncover mistakes and the word will spread of fortunes saved because of policy-based storage deployment. Some day VASA will be recognized as one of the great additions by vSphere 5.