September 06, 2016
I should probably explain that a bit. One of the turns OpenStack has taken the last couple of years is adapting based on influence from vendors (and some customers) wanting to make it look more like VMware. So it’s only natural that with all the talk about VVols in the past year or so that these same folks would naturally start thinking, “Yeah, we need that in OpenStack.” Here’s the secret, though: You already have this sort of functionality in OpenStack. In fact, it’s been there since day one.
Let’s be clear, though, the context of this discussion is specific to Cinder block storage. We’re not talking about Manila or shared file system-type storage here. Manila targets its own specific set of use cases; I won’t try and discuss the capabilities and functions of file shares in OpenStack.
The gist of what VVols and storage policy-based management is trying to get at is more granular control of storage. In VMware, traditionally you carve out a big LUN, throw VMFS on top of it, and share it across your guests. For a while now, VMware users have been asking for more granular control. More specifically, they want performance levels that match the workloads they’re running. This is where VVols comes into play.