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One of the biggest talking points coming out of the vSphere 6 release was VMware's focus on storage, specifically Virtual Volumes (VVOLs). The addition of VVOLs expands VMWare's software-defined storage capabilities by enabling storage arrays to be virtual machine-aware. Since VMware already has VSAN, the addition of VVOLs in vSphere 6 adds a new wrinkle to the storage world. This month, we asked our Advisory Board how VSAN and VVOLs affect how storage is looked at and purchased. How does this affect companies like Tintri and Tegile, that might be selling products with built-in features? What should users consider when it comes to choosing both storage hardware and software?
Rob McShinsky, Dartmouth Hitchcock Medical Center
Software-defined storage is a hot topic right now with lots of players on the court. VMware’s offering of VVOLs and VSAN technology is also taking a shot in this game and adds to their portfolio like NSX, to attempt to completely control all the major resources of the data center, compute, storage and network. VVOLs and VSAN technology are great offerings wrapping storage performance, policies and fault tolerance together and, at the same time, integrating with the complete vSphere line. It is only software however, so your choice of storage platform to incorporate this technology will most likely come down to the age-old brand loyalty versus price. There are a lot of vendors in this space right now using flash/SSD drives. In some cases the broadening use of flash drives makes up for bad SDS even with larger vendors, so it's important to be careful. Big names traditionally provide longer product lifespans, whereas smaller vendors, like Tintri and Tegile, often provide advanced and innovative features. I have worked with some great smaller companies. In most cases, if their technology is good, they are purchased by larger companies. Knowing your business model and exact level of risk is important.
Beyond the hardware decision, consider how VVOLs and VSAN technology changes your staff roles. This will thrust virtualization administrators into the role of storage administrators. Virtualization administrators usually have a pretty good understanding of storage needs, but this will pose a risk to overall environmental stability. As simple as the setup VVOLs and VSAN can be, it is far from "set it and forget it". Keep your existing storage team close if you have one. They are well versed in IOPs, cache, and controller technology that all make the storage tier unwavering. Bring them into the design mix if you have such people in your team.
Brian Kirsch, Milwaukee Area Technical College
A few years ago the buzzword was "the cloud" and if you didn’t move to the cloud you were in trouble. While the cloud has come and found its place, it didn’t signal the end to the folks who didn’t adopt it on day one. Storage is undergoing the same transformation with technologies such as VVOLs and VSAN. Storage frames have been around for a very long time and, to a degree, have been relatively unchanged for several years. While virtualization has changed the data center, storage was a unique category that did not lend itself to be virtualized easily due to both bandwidth and performance needs. Technology did catch up to the needs of storage, and combined with the complexity of managing storage it has helped to bring about new ways to look at storage.
Storage is no longer the island of the data center. Higher networked bandwidths have given rise to using local host storage over the more expensive shared storage SAN offerings, while still retaining performance and redundancy. VSAN and VVOLs are bringing the features and management aspects from the larger storage frame down to the hypervisor layer without the same costs as the traditional frame. While these benefits come at a lower cost, there is a tradeoff. A software-based storage solution still requires storage behind it and while the software layer abstracts the physical storage details, the hardware does still exist.
What this means for the organization is you cannot simply use VSAN and expect the same performance as an EMC vMAX. While this sounds great for the larger storage frame sellers, they can’t breathe easy just yet. For many applications in the data center you don't always need the massive performance of an enterprise storage frame. So while the enterprise frame is not going away, its role in the data center will diminish with some of these new offerings.
Software-defined storage is not one size fits all approach. Storage needs are made up of critical and archival data that don’t always fit an exact hardware configuration such as the all disk or all-flash frames. Being able to configure, deploy and manage storage via software might just be the answer the industry needs, however for the software to be effective you still need the right hardware for your business to base it on. Storage is still storage, even with a software layer on it.
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