Most hyper-converged products are based on commercial hypervisors, such as those from VMware and Microsoft, but...
there are a handful of hyper-converged vendors that use their own hypervisors.
It might be tempting to dismiss hyper-converged products that don't use hypervisors, such as vSphere or Hyper-V, but there are advantages to using an HCI system with a dedicated hypervisor. However, there are some disadvantages that organizations must weigh against the benefits that an appliance-specific hypervisor might provide.
Banking on benefits
Perhaps the greatest benefit to using an HCI product that relies on a proprietary hypervisor is that it is built specifically for the task at hand. The vendor presumably designed its hypervisor to do one thing, and to do it well. The end result is optimized, turnkey hyper-converged products.
Using a system based on a dedicated hypervisor may also reduce cost and complexity. The big hypervisor providers charge a premium for licenses, and companies might also incur additional costs in the form of support infrastructure, such as management or license servers.
An HCI product's hypervisor might also be easier to use than a general purpose hypervisor. Products such as vSphere and Hyper-V can be difficult to use because of the sheer number of features they offer, and because they must maintain backward compatibility. HCI-specific hypervisors might pose the same problem, but they are less complex overall, which should reduce the challenges associated with backward compatibility.
HCI-specific hypervisor drawbacks
One potential disadvantage to using an HCI product's hypervisor is a lack of support. Reputable vendors provide technical support services, but IT administrators often try to diagnose a problem themselves before calling technical support.
Hypervisor suppliers have many customers, and there are vast resources available online to help admins deal with nearly any problem imaginable. Typically, there are far fewer online resources to turn to for help with diagnosing problems with a hypervisor that is dedicated to one HCI system.
Another disadvantage to using hyper-converged products that are built around a proprietary hypervisor is that such systems may not mesh well with your existing infrastructure. For example, the virtualization management tools that are currently in place in an IT system probably won't recognize a dedicated hypervisor.
Likewise, there is a good chance that your already-deployed backup software isn't natively capable of backing up such a system. The hypervisor vendor may provide plug-ins for various backup applications, or IT admins may have to resort to performing guest-level backups. In any case, companies should definitely talk to the vendor about possible backup options before investing in a product.