Hyper-converged infrastructure (HCI) are specific solutions that combine computing and storage (and sometimes also networking) capabilities from more hosts to achieve a shared pool of resources. A vSphere cluster already does this for the computing part. Some storage products extend this to the storage part, making more external storage unnecessary and making the HCI market an important trend; it is not only growing fast, with more attention from the big storage vendors, but it is also changing fast.
We have already discussed HCI hardware in Chapter 2, Designing and Planning a Virtualization Infrastructure, so let's focus on VMware vSAN, the software-defined storage from VMware.
Note that there are also some specific HCI solutions for ROBO scenarios, or small clusters (usually HCI starts from at least three nodes), for example, from StarWind or StorMagic...
