Experiments in Geekery

I find OEM incredibly hard to work with.  Not while it's running as it's actually a nice product from a user perspective, but keeping it working always seems like a huge hassle. This is partly because my knowledge of Weblogic is minimal, and partly because the documentation doesn't really explain where one thing starts and the other ends.  When I'm configuring something, am I configuring Weblogic, or am I configuring OEM?  It's not always clear. So, we come to today's issue. The target:  /EMGC_GCDomain/GCDomain/EMGC_ADMINSERVER/wsm-pm  was showing as down after a restart of the OMS.  I tried starting it from within OEM, which complained because it's not possible to control Weblogic through OEM, which makes sense. I logged in to the Weblogic console, and navigated to GCDomain->Deployments, located wsm-pm in the list, went to the Targets tab and EMGC_AdminServer wasn't in the list of targets!  Sounds like a s imple fix, then.  Click Lo...

A thing that I repeatedly forget is how to do this.  I'm writing it down in the vague hope that I'll remember next time. Take running database, already monitored by OEM 12c.  Install new version of Oracle Home using OUI.  Try to use OEM 12c to upgrade database, but find that OEM doesn't know about the new home. How do you add the new home?  "Add target" menu doesn't work.  Where is it? Instructions are here:  https://docs.oracle.com/cd/E24628_01/doc.121/e24473/discovery.htm#EMADM13141 The secret is to create a new job, of the "Discover Promote Oracle Home Target" type.  Add in the path to the Oracle Home, let the job run, and voila.  Your new Oracle Home is now available.