Requiring an HMC
As a final exercise, you will make the PowerVM Server require a Hardware Management Console (HMC). Although there are situations where a HMC isn't strictly needed, such as with a standalone server or server with an IVM, in practice and for our purposes here, consider an HMC a requirement.
- Using the same topology as before, you will start by creating an HMC. The Hardware Management Console is an x86 server with a customized version of Linux. By now, you already know how to model this by using an x86 Server unit and a Linux unit.
- Add an HMC stereotype to the x86 Server.
- To make things a bit more interesting, change the appearance of the unit to make it stand out. You can do that by using the Appearance properties tab and selecting a different appearance from the list.
Figure 45 shows the HMC in tones of green.
Figure 45. Adding an HMC
You can add this stack composed of the server and the OS to the palette if you wish. The palette can contain templates composed of several units and relationships.
You need to make the PowerVM Server depend on at least one HMC. This means that you need to create a mandatory dependency requirement on the PowerVM Server unit.
- In the Requirements tab of the PowerVM Server unit, click the Add Requirement icon positioned above the requirements editor.
Needs HMCas the value of the Caption, set the Link type to dependency, and set the Type to server.X86Server.
Figure 46 shows the requirement added.
Figure 46. Adding the requirement to the PowerVM unit
- This requirement is set on server.X86Server, which is not specific enough. Therefore, add a constraint to the Needs HMC requirement to the HMC stereotype.
Figure 47. Adding a constraint
If you try to create a dependency link between the Power VM Server and the HMC, a pop-up window will appear showing the matching between requirements and capabilities. As can you can see in Figure 48, there is no 100% match between the requirement that you specified and the capabilities of the HMC unit. The reason is the same as in the previous sections: the dependency is enforced based on the stereotypes of the capability, not the unit itself.
Figure 48. Matching requirements and capabilities
You need to add the HMC stereotype to the server.X86Server capability of the HMC.
- Go to the HMC unit Capabilities tab, select the x86 Server capability, and add an HMC stereotype.
Figure 49. Adding the stereotype to the server capability
- This time, use the PowerVM Server warning icon to create the dependency link. Click the warning icon of that unit.
- When the warnings pop-up window appears, as seen in Figure 50, double-click the proposed action to create a dependency link to the x86 Server unit.
Figure 50. Creating the dependency link
Your model is now error-free.
Figure 51 shows the topology in its final state. You took it through several stages, each one building on the previous. Now you can use it for modeling not only LPARs but also virtual devices and HMC requirements.
Figure 51. The final topology