text: Figure 2-5 Docker engine versus virtual machine 
  
  The synergy of combining virtual machines and containers empowers the system 
  administrator to better tune the resources (processors, memory, storage, and network). They 
  also can optimize the overall usage of the available assets to maximize and simplify the use of 
  the physical hardware. 
  
  For management and infrastructure nodes of a cloud cluster, the use of virtual machines 
  might have more advantages. The system administrator has robust control of the resources 
  that are assigned to these nodes, which makes it easy to maintain the nodes as active and 
  well-tuned. 
  
  The decision to run it on a virtual machine or in a bare-metal machine must follow largely the 
  non-functional requirements of the architecture decisions. You can also take advantage of the 
  virtual resources that are provided by a virtual machine. Containers can interact with virtual 
  machine-provided services. For example, your application containers must interact with a 
  database that uses storage that is backed by volumes that are managed through IBM 
  PowerVC. 