The Beauty of MinRoleSharePoint 2016 introduced a host of new features, including MinRole. MinRole promised easier administration of SharePoint servers. You can read about how it was touted to simplify deployment, improve performance and reliability, and simplify capacity planning and farm scalability here, All you had to do when you installed SharePoint 2016 was select one of the predefined roles in the configuration wizard:
If you selected "Front-end", "Application", "Distributed Cache", or "Search", SharePoint would take care of installing the appropriate bits and turning on the appropriate services on the server.
Microsoft had learned a lot from running SharePoint at a massive scale in Office 365. They were passing that learning on to us.
The Problem with MinRoleThe problem with MinRole at RTM was that it was generally more beneficial for companies that ran large farms (much like Microsoft did in the cloud). If you wanted to run a highly available MinRole farm that also runs workflow and office online server, you would generally need about 15 servers for just one environment:
For many small to mid-size organizations that want to keep their SharePoint environment on premises, this is a lot of infrastructure, especially considering that most organizations need at least two more environments: Staging and Disaster Recovery. MinRole, just wasn't an option...so Custom was the option to select in the Configuration Wizard...no different than how it would be done in SharePoint 2013.
The SolutionStarting with the November 2016 Public Update for SharePoint Server 2016 Microsoft introduced the concept of Shared roles. Instead of each server having 1 of 4 distinct roles, servers could now share roles. So, Front End and Distributed Cache could be combined and Application and Search could be combined. The new configuration wizard now looks like this:
A fully built out, highly available SharePoint 2016 farm using shared min roles was now 11 servers instead of 15, which is a little easier to swallow, especially considering many small organizations don't implement the workflow functionality and would only have 8 servers