The management components of a virtual environment can be resource intensive. If you are running vCenter and its dependencies as virtual machines in the same cluster as the cluster managed by the vCenter server, the resources required by the management infrastructure must be factorized into the capacity calculations of the logical design. Creating a separate management cluster separates the resources required by the vCenter components from the resources required by the applications hosted in the virtual infrastructure.
Management cluster best practice is as follows:
CPU and memory resources to support management applications
Multiple network interfaces and multiple physical network switches to minimize the single points of failure in the management network
Multiple paths to the storage in order to minimize the single points of failure in the storage network
Storage designed to support both the capacity and the performance required for management...