Central agent is the Oracle Management Agent (Management Agent) that is deployed by default with the first Oracle Management Service (OMS). In Enterprise Manager Cloud Control 12c Release 1 (22.214.171.124) and 12c Release 2 (126.96.36.199), by default the agent base directory of the central agent was maintained inside the Oracle Middleware Home (middleware home). However, in Enterprise Manager Cloud Control 12c Release 3 (188.8.131.52) or higher, Oracle strongly recommended that you maintain the agent base directory outside the middleware home, although you could choose to maintain it inside the middleware home. While upgrading from 12c Release 1 (184.108.40.206) or 12c Release 2 (220.127.116.11) to 12c Release 3 (18.104.22.168) or higher, you had the option of migrating the agent base directory to a location outside the middleware as described in Moving the Central Agent Base Directory Outside Oracle Middleware Home. If you had already migrated the central agent, then you can directly remove the old OMS home. Otherwise, you must first migrate the central agent and then remove the old OMS home.
This appendix describes how you can remove the old OMS home under both these circumstances. In particular, it covers the following: