Console Counseling

Having a Hardware Management Console (HMC) in your environment has its benefits. You can remotely power a machine on and off. You can remotely get to a console from the HMC. You can use the HMC to create logical partitions. And, should problems arise with the actual POWER server or the HMC, IBM can help you. If you're using another vendor's solution for your remote console and remote "power off and on" solutions, who knows what kind of support you might get from them if things are not working properly.

After running your machine in stand-alone mode with an async terminal for a console, you may have an issue defining your console after you attach it to the HMC. Sometimes when logging into the HMC and trying to bring up a console window, I've seen strange characters on the screen, or no characters at all. I call this gobbledygook, though I'm not sure that phrase translates well for our international readers.

In one scenario, IBM Support had me remove devices from the ODM and then reboot, so that it would give me the opportunity to select the console. On another occasion, the machine was still in manufacturing default configuration (MDC) and IBM had a document that advised us to take it out of MDC. In each case, the console worked fine once I followed IBM's suggestions.

I thought I'd pass on these items should you ever find yourself with a non-working console from your HMC. If you click on the links below, you can find information on the problems and the solutions.

• "Problem: Terminal window to the default partition is unusable on new managed systems due to system being in MDC. Symptom: Users receive garbage characters on terminal window to newly added p5 or p6 managed systems or do not get a login prompt once default partition is activated."
• "Problem: System p is newly attached to an HMC and the server property for MDC is false. The vterm console works in hardware mode (i.e., SMS and for displaying hardware parameters when LPAR is activating). However, the vterm does not display login prompt after AIX has been booted. Cause: AIX was installed on system p server when it was attached to an async console prior to attaching system to HMC."

Read both of these links and add them to your toolkit. As always, if you get stuck, call IBM Support. They will know how to help you.

Comments

[Chris Gibson]

Another great post. Your tips are always useful.....and my AIX toolkit is much better for it!

I've come across this issue over the years....even on p650 and p690 servers.

I managed to workaround or fix this issue via several kludgy methods. Nice to see a supported method of resolving the problem.

Cheers.

Chris

[Gibbo]

Stumbled across one of my old methods of resolving this type of problem (only used this on the default, AIX pre-installed, LPAR):

"The function of devreset (full path /usr/sbin/devreset) is to rebuild
the device ODM database and reset all devices to default configurations.
devreset does this by rebuilding all Cu* (Customized Device Attributes) in
/etc/objerepos and deleting non-standard /dev special files. devreset
asks for interactive confirmation before making any changes (unless the Force
option is invoked), and the old device attributes and special files
are backed-up in a save directory (see -A and -R flags bellow).

** WARNING: Running devreset on a live system can result in process **
** disruption. You must halt the system immediately after devreset **
** completes. **

Example:
# devreset"

Have a look at /usr/lpp/bos/README.PARTITION_INSTALL for more information. I don't recommend using it but it's interesting reading!

Chris.