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Galaxy Configuration Models  



The GCU is a fully programmable display engine. It uses a set of rules to learn the desired characteristics and interactive behaviors of the system components. Using this specialized configuration knowledge, the GCU assembles models that represent the relationships among system components. 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 routines 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 configuration to match the model. Whether you are viewing the active model or an offline model, you can save the current configuration as an offline Galaxy Configuration Model (.GCM) file.

To make an offline model drive the current system configuration, the model must be loaded and engaged. To engage a model, click the Engage button. The GCU scans 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 final confirmation. If you approve, the GCU executes the actions, and the model is engaged to reflect the current system configuration and state.

When you disengage a model, the GCU immediately marks the CPUs and instances as off line. You can then arrange 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 useful for your business operations. These can be engaged by a system manager or a suitably privileged user, or through DCL command procedures.

Active Model  

The GCU maintains a single active model. This model is always 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 integrity 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.

Offline Models  

The GCU can load any number of offline Galaxy configuration 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 represent new Galaxy innovations. Note this fact if you decide to explore the model and ruleset files directly. If you accidentally corrupt a model, you can always generate another. If you corrupt the ruleset, you may need to download another from the OpenVMS Galaxy web site.

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 extension. It is useful to give the model a name that denotes the CPU assignments; for example, 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 CPUs 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 is loaded and displayed in an offline, disengaged state.
  5. Click the Engage button to reengage the model.
  6. The GCU displays any management operations required to engage the model. If you approve of the actions, click OK. The GCU performs the management actions, and the model is displayed as active and engaged.

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