VMware has been in the works for a software SAN also known as VSAN. The technology functions with up to 8 nodes in the current beta and will support 32 once GA. Also vmware purchased Virtso which is an incredible storage software solution that virtualizes storage and re-orders the write patterns to sequential. Take a look below at the demo from Rawlinson Rivera (@punchingclouds) VCDX #86.
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@keithnorbie virtual ideas 
what an awesome video, and I love the orange jacket. The only thing is that VSAN will not support 32 nodes when the product is generally available. We’re looking to hopefully support 16 nodes by GA but is not a promise. Reaching that goal of 32 nodes will be a gradual progression as we continue to improve the platform. Thanks for the interview.