How to Uninstall the Agent Oracle Home that Registered with Inventory

A long title for a short trick. I have uninstalled my cloud control agent and tried to re-install it. I gave the same directory I previously used to install and EM Cloud Control Agent Deploy Wizard gave an error at remote prerequisite check:

So it says I should deploy to a different directory or uninstall the Agent Oracle Home already registered. Because of our deployment standards, I need to deploy this agent to the same directory so I searched how I can uninstall the Agent Oracle Home.

How to Deploy Oracle Management Agent 12c

In my previous post, I tried to show how to install Enterprise Manager Cloud Control 12c, now I’ll show how to add target hosts to our Enterprise Manager system. I assume that you’re in a similar position (installed Cloud Control but haven’t added any target yet).

As you know, we have to install Oracle Management Agent to the targets to be able to manage them via our Enterprise Manager. In OEM Cloud Control 12c, we can “Add Host Targets Wizard” which is accessible from the web interface. We can manually enter required information of host or we can use auto-discovery method.

If we’ll use auto discovery, we need an active agent to discover targets in network. This agent can scan local services or network. “Nmap” is used for scanning network. Nmap requires root privileges to be able to use raw sockets for “Syn Scanning” (a method to detect open ports through firewalls). So we need to configure “privilege delegation” in the host of our agent (which we’ll use for scanning).

How to Install Oracle Enterprise Manager Cloud Control 12c

Installing Oracle Enterprise Manager Cloud Control 12c is easy and it’s already explained in a video at OTN website and MOS [ID 1359176.1]. Still, I wanted to create a step by step guide, and highlight the important points.

Here are the steps:

1) Installation of Oracle Linux (How to Install Oracle Linux 5.6)
2) Installation of Oracle Database (Repository Database): You can install one of the certified databases:,,, and

Do not forget to apply the latest PSU to the database. It is recommended that you do not use “memory_target” parameter with Enterprise Manager. Run the following commands and bounce the database:

These are minimum values, you can set higher values according to your system resources. It’s also recommend to have at least 3 redo log groups sized 300M. Luckily, the installer will warn you about all these settings.

Oracle Unveils Enterprise Manager Cloud Control 12c

Yesterday (October 03), Oracle announced Oracle Enterprise Manager 12c (c for cloud). It’s the only complete management solution for enterprise cloud. Oracle Enterprise Manager is the first “12c” Oracle product. I’m sure that we’ll see more “12c” products in future.

You can read the press release of Oracle Enterprise Manager 12c:

I have noticed that Oracle Enterprise Manager Cloud Control is mentioned in all keynotes at Oracle Open World 2011. In my opinion, Oracle Enterprise Manager Cloud Control and Ops Center are the key components of the cloud environment. You can read what Oracle Partners are saying about Oracle Enterprise Manager 12c: