A lot of storage providers, professionals and pundits are talking about VVol; and they’re not always saying the same things. As a result, some myths are making the rounds, and it’s time they were busted. Below are the 7 big myths and simple explanations of storage reality.
You need one VVol for Config, one for Swap and one for each vDisk. That’s a minimum of three per VM. Then, for every snapshot you need one more VVol for each vDisk and one Memory VVol per snapshot. Bottom-line: you might need hundreds (or even thousands) of VVol for one VM.
In fact, the number of VVol a conventional storage provider can support with 4U of rack space can vary from <200 to approximately 10,000. Since Tintri is already built to operate exclusively in virtual machines, a single VMstore T880 can support 1,000,000 VVol—that’s 100x conventional storage. Given the first myth (how quickly your VVol count will grow), you should look for a vendor that can support a LOT of VVol.
VVol isn’t a product, it’s an API. So, VVol functionality is entirely dependent on your storage providers’ underlying structure and ability to implement VVol. Providers with LUN and volume-based architectures will struggle to digest the API.
You have to upgrade to vSphere 6 (or later). And you will probably need to upgrade the firmware on your array. And not all arrays are VVol ready, even in the same array family. Oh, and each array will implement VVol differently with different limitations. In short, there’s a lot for customers to think through.
Once the VVol API places a VM, it is up to the array to provide QoS and other policies—and those are still enforced by the storage array at the Storage Container or Volume/LUN level, not for each VM. You might have to learn to live with those noisy neighbors.
Actually, not all VMware products support VVol, including vROps, vCloud Air, Site Recovery Manager and more. And, not all vSphere 6.0.x features operate with VVol—namely Storage Distributed Resource Scheduler and array-based replication. Keeners are encouraged to check out VMware KB 2112039 for the complete list.
VVol allow you to choose VM-level services the storage admin has already set up—the Virtualization admin can select desired performance policies for each VM. However, it does not set or guarantee performance, it merely determines what Storage Container the VM will fall into.
One thing that’s not a myth is that Tintri will have the best implementation of VVol. The reason is simple—every other storage vendor is built to handle physical workloads with LUNs and volumes; Tintri is entirely focused on virtualization and so we let you manage only what matters… virtual machines. As true VM-aware storage, not only will you get the best VVol implementation, but you can enjoy VM-level management right now—across vSphere 4, 5, and 6, plus Hyper-V, RHEV and OpenStack.
Unique control with VM-level actions for infrastructure functions including snapshots, replication and QoS make protection and performance certain in production, and accelerate test and development cycles.