9.3 Galaxy Configuration Models
The GCU is a fully programmable display engine. It uses
a set of rules to learn the desired characteristics and in-
teractive behaviors of the system components. Using this
specialized configuration knowledge, the GCU assembles
models that represent the relationships among system com-
ponents. The GCU obtains information about the current
system structure by parsing a configuration structure built
by the console firmware. This structure, called the Galaxy
Configuration File, is stored in memory and is updated
as needed by firmware and by OpenVMS executive rou-
tines to ensure that it accurately reflects the current system
configuration and state.
The GCU converts and extends the binary representation
of the configuration file into a simple ASCII representation,
which it can store in a file as an offline model. The GCU
can later reload an offline model and alter the system con-
figuration to match the model. Whether you are viewing the
active model or an offline model, you are always free to save
the current configuration as an offline Galaxy Configuration
Model(.GCM)file.
To make an offline model drive the current system config-
uration, the model must be loaded and engaged. To engage
a model, click the Engage button. The GCU will scan the
current configuration file, compare it against the model, and
create a list of any management actions that are required to
engage the model. The GCU presents this list to you for fi-
nal confirmation. If you approve, the GCU will execute the
actions, and the model will become engaged to reflect the
current system configuration and state.
When you disengage a model, the GCU immediately marks
the CPUs and instances as offline. You can then freely ar-
range the model however you like, and either save the model,
or reengage the model. In typical practice, you are likely to
have a small number of models, that have proved to be use-
ful for your business operations. These can be engaged by
a system manager or a suitably privileged user, or through
automated procedures or batch job.
9.3.1 Active Model
The GCU maintains a single active model. This model is al-
ways derived from the in-memory configuration file. The
configuration file can be from a Galaxy console or from a
file-based, single-instance Galaxy on any Alpha system.
Regardless of its source, console callbacks maintain the in-
tegrity of the file. The GCU utilizes Galaxy event services to
determine when a configuration change has occurred. When
a change occurs, the GCU parses the configuration file and
updates its active model to reflect the current system. The
active model is not saved to a file unless you choose to save it
as an offline model. Typically, the active model becomes the
basis for creating additional models. When creating models,
it is generally best to do so online so that you are sure your
offline models can engage when they are needed.
9.3.2 Offline Models
The GCU can load any number of offline Galaxy configura-
tion models and freely switch among them, assuming they
were created for the specific system hardware. The model
representation is a simple ASCII data definition format.
You should never need to edit a model file in its ASCII form.
The GCU models and ruleset adhere to a simple proprietary
language known as the Galaxy Configuration Language
(GCL). This language continues to evolve as needed to rep-
resent new Galaxy innovations. Beware of this fact if you
decide to explore the model and ruleset files directly. If you
accidentally corrupt a model, you can always generate an-
other. If you corrupt the ruleset, you may need to download
another from the OpenVMS Galaxy website.
9.3.2.1 Example: Creating an Offline Model
To create an offline Galaxy configuration model:
1. Boot your Galaxy system, log in to the system account,
and run the GCU.
2. By default, the GCU displays the active model.
3. Disengage the active model by clicking the Engage button
(it toggles).
4. Assuming your system has a few secondary CPUs, drag
and drop some of the CPUs to a different Galaxy instance.
5. Save the model by selecting Save Model from the Model
menu. Give the model a suitable name with a .GCM ex-
tension. It is useful to give the model a name that denotes
the CPU assignments; for example, such as G1x7.GCM
for a system in which instance 0 has 1 CPU and instance
1 has 7 CPUs, or G4x4.GCM for a system with 4 CPU on
each of its two instances. This naming scheme is optional,
but be sure to give the file the proper .GCM extension.
You can create and save as many variations of the model
as you like.
To engage an offline model:
1. Run the GCU.
2. By default, the GCU displays the active model. You can
close the active model or just leave it.
3. Load the desired model by selecting Open Model from the
Model menu.
4. Locate and select the desired model and click OK. The
model will be loaded and displayed in an offline, disen-
gaged state.
5. Click the Engage button to reengage the model.
6. The GCU will display any management operations re-
quired to engage the model. If you approve of the ac-
tions, click OK. The GCU will perform the management
actions, and the model will be displayed as active and
engaged.