With VMware’s announcement of vSphere 6.0, we’ve had a lot of new topics to write about. I’ll be focusing this post on VMware interpretations and implementation of software-defined storage and on the enhancements of VMware Virtual SAN 6.0 in particular. VMware’s strategy is to push for change by driving transformation through the hypervisor until we get to a completely software-defined data center, with all available resources presented and controlled via the hypervisor.
VMware aims to transition from the “legacy” storage model with an approach promising a more flexible and efficient storage model in virtual environments. In this, VMware is playing catch up with Microsoft on utilizing local disks of the physical hosts as logical pools of storage capacity. Keeping true to its roots, VSAN is hardware-independent and works with any x86 Server that is on the vSphere Hardware Compatibility List (HCL), allowing customers to continue working with their vendor of choice. VMware VSAN 6.0 has three different deployment options available, letting customers build their own configuration with a component-based approach, take advantage of the ever-growing Virtual SAN Ready Node offerings, or buy into VMware’s EVO:RAIL compute systems.
The pros and cons of these solutions are all over the Internet, often in great detail. Rather than rehash this, I ask the following question: who are the main consumers of VSAN technology?
Let’s think about this for a second. If you were a company with a well-established virtual or cloud infrastructure running on a physical SAN, what would drive you to walk away from the big money you’ve invested into the physical storage system? VMware had a much easier sell when it was pushing the virtualization of servers in the early days. It is one thing in both cost and effort to virtualize a server and an entirely different thing when it comes to virtualizing the SAN. It’s also noteworthy that storage systems have exploded in both size and scope from the pre-virtualization days of the last century, with much of that growth driven by virtualization itself.
On the flip side of that coin, “smaller” IT shops with less than three physical hosts can’t take advantage of in situ SAN technology, and using it will require an investment in the underlying hardware and storage. Now, for a shop making the transition, with a few 4U servers with plenty of drive bays ready to repurpose, this may not be that big of a deal. If your facility has already sprung for smaller physical hosts, such as modern blade systems, without those excess drive bays, the next logical choice may just be the Virtual SAN Ready Node.
Regardless of the choice, there are new upfront costs associated with the migration to Virtual SAN. Just like server virtualization, that upfront investment may lead to substantial overall hardware savings in the years to come after deployment.
In closing, I think the VSAN technology has the potential to really take off and redefine the concept of storage in a virtual environment. The transition is going to be a long road, with lots of bumps and diversions. In the end, it should be a real game-changer in the data center.