Per Oracle documentation, you’re able to upgrade from EM12c to EM13c, including the OMR, (Oracle Management Repository) to DB12c and the OMS, (Oracle Management Service) to EM13c, but leave the agent software at a version of 18.104.22.168 or higher, leaving upgrades of the agents to be performed later on using the Gold Agent Image, removing a lot of work for the administrator.
This is a great option for many customers, but what if your existing EM environment isn’t healthy and you need to start fresh? What options are left for you then?
I’ve covered, (and no, it isn’t supported by Oracle) the ability to discover a target, doing a silent deployment push from the target host back to the OMS using a 22.214.171.124 software image by simply adding the -ignoreprereqs argument. This does work and will deploy at least the last version of EM12c agent to the EM13c environment. What I don’t know- If you have an installation of software that was upgraded to a supported version in the past, (i.e. 126.96.36.199 upgraded 188.8.131.52, etc.) I haven’t tested this and I can’t guarantee it, but it’s worth a try. Same goes for an unsupported OS version, but I think if you choose to push the deploy from the target and choose to ignore the prerequisite checks, it may successfully add the target.
If you have an earlier version of EM12c agent, 184.108.40.206 to 220.127.116.11 that can’t be updated to EM13c, there is still hope outside of what I’ve proposed. The word on the streets is that with the release of 13.2, there will be backward support of earlier versions of agent software and that WILL be supported fully by Oracle.
That also offers a silver lining for those that may be considering going to EM13c, won’t be upgrading and want to take advantage of redirecting existing targets with EM12c agent software to the new installation. I’m assuming they’ll simply run the following command to redirect those targets, (or something close!):
emctl secure agent <new EM_URL and credential information>
I have high hopes for this option being available in 13.2 and will cross my fingers along with you.