The
GCU allows you to display and interact with the active (online)
or inactive (offline) Galaxy configuration models. When the configuration
display represents a model of the active system, the GCU displays
the state of the CPUs and instances using color and text. When the
configuration model is engaged in this manner, you can interact
with the active system using drag-and-drop procedures. The formal
description for this mode of operation is interacting with the engaged,
online model.
GCU users can also interact with any number of disengaged,
or offline, models. Offline models can be saved to or loaded from
files. An offline model can also be derived from the active online
model by clicking the Engage button to be disengaged when the active
online model is displayed. In addition to the visual state of the Engage
button, the GCU also indicates the online versus offline characteristic
of the CPUs and instances by using color and text. Any drag-and-drop
actions directed at an offline model are interpreted as simple editing functions.
They change the internal structure of the model but do not affect
the active system.
When an offline model is engaged, the GCU compares the structure
of the model with that of the active system. If they agree, the
offline model is engaged and its new online state is indicated with
color and text. If they do not agree, the GCU determines what management
actions would be required to alter the active system to match the
proposed model. A list of the resulting management actions is presented
to the user, and the user is asked whether they would like to execute
the action list. If the user disapproves, the model remains off
line and disengaged. If the user approves, the GCU executes the
management actions and the resulting model is displayed as on line
and engaged.