General Concepts » Depedency


Dependency is the term for relationship between pieces of infrastructure.  Rarely are pieces of infrastructure stand alone in an environment.  Consider all of the infrastructure needed to make a Virtual Machine available on the network:

  • ESX Environment.  The Virtual Machine does not exist without the vSphere environment with its software and operations team.
  • ESX Hosts.  The ESX environment cannot exist without ESX Virtual Hosts to provide the CPU, memory and network infrastructure to run the virtual machines.
  • Storage.  The ESX Environment cannot deliver services without a SAN in place to allow Virtual Machines to have disks.
  • Networking.  Storage Networks, Data Networks, Firewalls and switching equipment are needed to tie all the infrasturcture together.
  • Datacentres.  A datacentre with racking power and operational teams is needed for any of the physical hardware to be operated.

cloudstep models and visualises this information clearly as a graph

cloudstep models this complex relationship in order to tell us important information:

  • How much does the Virtual Machine cost to operate per month?
  • As we migrate applications out of the datacentre we don't need the virtual machines anymore, when could we turn the ESX environment off?