A lot of people don't want third party tools that come from an unknown source. That the DRBD feature is totally built into the kernel and there just waiting to be exposed with an interface is a big deal that makes users feel much better than getting the actual functionality from a different company.
Again, we would only do this if business needs require it. But my question is more centered around how people get the gear to fully test out VSAN and do a proof of concept before they deploy it?
Bigger companies that care about testing maintain labs with lots of hardware to test this stuff. That's the price paid for all kinds of necessary testing.
And I am certain their internal IT is much larger than our 4-person team.
With a small team you are stuck leveraging: reviews, logic, anecdotal evidence, vendor reputation and guesswork. Just the nature of being small. Leverage what the big boys do, applying logic as to when what they do matters only at their scale rather than at yours. The way that SMBs compete is by not doing all of the expensive lab work and trusting the work of others. The way that enterprises compete is by doing their own research better than someone else does it and getting a technical advantage.
One is about blazing new ground, the other is about running agile and low cost.