3.2  Possible OpenVMS Galaxy Configurations

  TBS: In this section, give an overview of the mod-
  els of computing.  Then describe how the models
  "transform" into Galaxy configurations.

  An OpenVMS Galaxy computing environment lets customers
  decide how much cooperation exists between instances in a
  single computer system.

  In a shared-nothing     computing model, the instances do
  not share any resources; operations are isolated from one
  another.

  In a shared-partial    computing model, the instances share
  some resources and cooperate in a limited way.

  In a shared-everything      model, the instances cooperate
  fully and share all available resources, to the point where
  the operating system presents a single cohesive entity to the
  network.

  To be supplied:  Expand the descriptions of these
  models in the following sections.

  3.2.1  Shared-Nothing Computing Model
  In a shared nothing configuration, the instances of OpenVMS
  are completely independent of each other and are connected
  through external interconnects, as though they were separate
  computers.

  With APMP, all available memory is allocated into private
  memory for each instance of OpenVMS. Each instance has its
  own set of CPUs and an appropriate amount of I/O resources
  assigned to it.

  3.2.2  Shared-Partial Computing Model

  3.2.3  Shared-Everything Computing Model