I think ScaleIO already has some features for scalability as it is part of the reason for the product. But in terms of size, maybe they should try to address parent storage. In that area, they need to have more options.  

We have done, I think, only two implementations so far. There are some more going on, but these are only in the discovery phase. In the coming year, I expect that we will pick up more clients who will be implementing this product as a solution.  

The size of the user group of one of the implementations is about 100 plus users, and the other one is somewhere between 100 to 150 plus on a team. The second is only a little larger. Scalability per user does not seem to be much of an issue.  

Actually, ScaleIO has a limitation of 1000 nodes. We only built up 20 nodes as SDS; that's enough for us.