Discovery isn't what you would think from popular culture ... if you served my company with discovery request, "we" (all the lawyers and companies) would have a meeting about it -- you would want to extend your grasp, we would look to shrink it. Most of the time, you would end up with something like "All emails about 'blue paint' between April 2011 and March 2012". Then it is up to ME and my company to find all those emails and provide them to you. Even knowing my email provider would likely be outside the scope. Discovery isn't to FIND a civil issue, it is to find evidence of one already filed issue, so fishing is explicitly not allowed.
Corporate policies are a huge part of the discovery process, what makes it hellish is when you have NO policy around something (like email) because then you have to provide data or prove you don't have it. Our proof is our policy and technical measures.
Our lack of recording data (logging) IS our record management strategy (and a wholly valid one) that massively reduces our costs if we ever get sued.
The "cloud vendor's backup tape" is largely a straw man brought up by engineers rather than lawyers, I think I may have been guilty of bringing it up prior to learning about the discovery process.