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HMCs and BMC managed IBM PowerSystems - Should you connect BMC based systems to your HMCs?

How To


Some IBM Power Systems have a flexible service processor (FSP) and these systems are generally connected to, and managed by one or two Hardware Management Consoles (HMCs).

Other Power Systems have a Baseboard Management Controller (BMC) and can be controlled in a number of ways, including the Intelligent Platform Management Interface (IPMI) and the web-based graphical user interface (GUI). It is also possible to connect the system to an HMC. This article discusses the merits of doing so.




First, if you have a cluster of many (perhaps thousands) of BMC based servers, you are probably managing the servers in a different way.

Alternatively, if you have a number of FSP based serves and are familiar with the HMC, you might find benefits from also connecting up the BMC based systems.

You probably use the GUI on the HMC to have an overall view of the systems in your estate.  Like me, you might also use the HMC's command line interface (CLI) to run commands on all or some of your systems. For example, checking to see whether they are powered on or what level of firmware they have. There are many other things that you can do with an FSP based system and while you cannot do all of them with a BMC based machine, you can do some of them.

These reasons alone are enough to convince me of the benefit of connecting our BMC based systems to our HMCs.

Here are the actions available for a BMC based system via the HMC GUI:

BMC Server actions   

One key feature that you might notice is the ability to carry out updates. You can select multiple BMC based systems and update the firmware, which makes the process much more simple than having to go to each BMC GUI in turn to do it.

You also notice that you can use the HMC's Serviceable Events Manager to see any events that might occur on your BMC based system.

I see no downside in attaching a BMC based system to an HMC and several benefits. If you do connect them up, you can still use any, or indeed all, of the other methods for managing the BMC based system such as IPMI and the BMC's GUI.


So, how do you do it?
Clearly,  there has to be a network connection between the HMC and the BMC in the system. It does not have to be on the HMC/FSP private network, it can be between the BMC and any of the network ports on the HMC. They must each have a route to the other.
This page: Managing OpenBMC-based systems  Covers the different methods for managing your BMC based systems.
This one is specific to connecting to an HMC: Managing OpenBMC-based and BMC-based systems by using the HMC.
You can either add the system to the HMC in the GUI or the mksysconn command on the HMC's CLI.
Here is a screen capture of doing it via the GUI:
Connect using the HMC GUI
This code snippet shows the connection being made via the HMC's CLI:
  hscroot@hmc15:~>  mksysconn --ip  -u ADMIN  Enter the management console access password for the system:  hscroot@hmc15:~>
Obviously, you would use your own IP address, and I was using the default user "ADMIN" and entered the password when I was prompted.
Now the system shows up on the GUI.
As you would expect, it is possible to have some redundancy, your BMC based machine can be connected to two HMCs.

Additional Information

If you connect a BMC based system to dual HMCs but one of them calls home, once every 24 hours with E3325009, you need to apply an update to the HMC. If you have the latest level of HMC code, all of the BMC based systems can be connected to two HMCs and this error is prevented.

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Document Location


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Document Information

Modified date:
12 March 2020