Oracle Management Service Migration

Prerequisites Check

Before performing the OMS migration, complete the following prerequisites:

Check the operating system of the hosts.
The source and destination hosts must have the same operating system.

Note:
Cross platform OMS migration are not supported.
The Management Agent needs to get installed and running on the destination host (host where the OMS is going to get migrated) prior to starting the OMS migration process.
Once completed, verify the agent status on the destination host by running the following:
```
<AGENT_HOME>/bin> ./emctl status agent
```
Confirm the disk space available.
The minimum disk space available is 25 Gb in the destination host.
The software library location must be the same on both hosts. It must accessible and empty on the destination host.
As part of the migration process, files are copied over to the same location from the source to the destination host.

Perform Oracle Management Service Migration

After completing the prerequisites check, perform the following steps to migrate the OMS:

Step 1: Launch the Migrating OMS Deployment Procedure

A deployment procedure is a sequence of provisioning steps and phases where each phase can contain sequence of steps. The Migrating the OMS to another host deployment procedure is provided by Oracle to be used to perform OMS migrations.

During this step, the OMS files are being copied over from the source to the destination host.

To launch the Migrating the OMS to another host deployment procedure, do the following:

From the Enterprise Manager Console, click Enterprise.
Under Enterprise, click Provisioning and Patching and then Procedure Library.

The Deployment Procedure Manager page is displayed.
Under Search Text Field, enter Migrating the OMS to another host and click Go.

From the results, select the Migrating the OMS to another host deployment procedure and click Launch.
The OMS Migration Service wizard is displayed.
1. On the OMS Migration Service: Getting Started page, confirm that you completed the prerequisites by selecting the appropriate checkboxes and click Next.
  For details about the OMS migration prerequisites, see Prerequisites Check.
2. On the OMS Migration Service: Select Destination page, provide the following:
  - Destination Host: Host name where the OMS is getting migrated to.
  - Destination Instance Base Location: Location where the configuration files of the OMS migration service process are created. The location must be same on the source and destination hosts.
  Under Source Credentials, provide the credentials details of the user that owns the OMS software installation in the source host.
  
  Under Destination Credentials, provide the credentials details of the user that owns the OMS software installation in the destination host.
  
  Click Next.
3. On the OMS Migration Service: Options page, do the following:
  - Under File Transfer Options, provide the preferred transferred mode to copy files over from the source to the destination host to complete the deployment procedure process.
  - Under Staging Locations, provide the locations in the source and destination hosts to store the temporary files during the deployment procedure process. They will be cleaned up once deployment procedure is completed.
4. On the OMS Migration Service: Post Creation Steps page, review the information provided and click Next.
5. On the OMS Migration Service: Review page, review the details provided and click Finish to run the deployment procedure.

Once the deployment procedure is completed, connect to the destination host and perform Step 2: Run ConfigureGC Wizard.

Step 2: Run ConfigureGC Wizard

During this step, the OMS files are being configured in the destination host.

Prerequisite:

Confirm that all the OMSs are down: The source OMS and if applicable, its additional OMSs.

Configure the Migration

Connect to the destination host, go to the <OMS_HOME>sysman/install directory and execute the following:

./ConfigureGc.sh -omsmigration

The ConfigureGC wizard is displayed.

Select Migrate Enterprise Manager system and click Next.
Under Installation Details, review the destination host information.
The Host Name and Backup file location get populated automatically and cannot be edited.

Click Next.
Under Configuration Details, provide the database and WebLogic credentials information.
- The database connector details.
- The SYSMAN password.
- The WebLogic Server Administrator password.
- The Node Manager password.
- The Agent Registration password.
Click Next.
Review and click Configure.

Post Migration Tasks

The following steps should be performed to ensure that the Oracle Management Service (OMS) migration was successful:

Start the OMS.

Run the following:

<OMS_HOME>/bin> ./emctl start oms

The output looks similar to the following:

Oracle Enterprise Manager Cloud Control 13c Release 5
Copyright (c) 1996, 2020 Oracle Corporation. All rights reserved.
Starting Oracle Management Server...
WebTier Successfully Started
Oracle Management Server Successfully Started
Oracle Management Server is Up
JVMD Engine is Up

Verify the OMS status by running the following:

 <OMS_HOME>/bin/./emctl status oms -details

Secure the source OMS agent with the new OMS.
Confirm that the source OMS agent is up and running, then secure it with new OMS to relocate the targets.
Run the following command in the source OMS Agent server:
```
<Source_AGENT_HOME>/bin/emctl secure agent -emdWalletSrcUrl https://<NEW_OMS HOST_NAME. DOMAIN NAME>:<HTTPS UPLOAD_PORT>/em 
```
Refresh Weblogic Domain to reconfigure the domain with the new hostname.
In the Enterprise Manager Console, do the following:
- Navigate to Targets, Middleware and locate the WebLogic Domain(GCDomain) target.
- Right click on the GCDomain, select Target Setup and then, Monitoring Credentials.
- Update the Administration Server Host to the new OMS hostname and click Ok.
- Return to Targets and Middleware, right click on the GCDomain target and select Refresh Weblogic Domain.
- Click on Add/Update Targets and wait for the domain to refresh.
Relocate the source OMS Agent targets to the target OMS Agent.
To point all targets to new the agent, do the following:
- Navigate to Targets and All Targets
- Click GCDomain, select Target Setup and Modify Agents. Then, click Continue.
- Under Monitor All Targets Using This Agent, enter "<new Agent Hostname.domain name>:<port>" and then click Assign.
- The list is populated with <new Agent Hostname.domain name>:<port> under New Agent.
- Click Modify Agents.

Relocate the oracle_emrep target to the Management Agent of the new OMS host.

Run the following:

<OMS_HOME>/bin/emcli login –username=sysman
<OMS_HOME>/bin/emcli sync
<OMS_HOME>/bin/emctl config emrep -agent <new oms hostname.domain name>:<agent port>

For example:

<OMS_HOME>/bin>./emctl config emrep -agent <new oms hostname.domain name>:<agent port>
Oracle Enterprise Manager Cloud Control 13c Release x
Copyright (c) 1996, 2020 Oracle Corporation. All rights reserved.
Please enter repoEnter password : Login successful
Moved all targets from <old oms hostname.domain name>:<port> to <old oms hostname.domain name>:<agent port>
Command completedEnter password : Login successful
Moved all targets from <old oms hostname.domain name>:<port> to <new oms hostname.domain name>:<agent port>
Command completed successfully!
<OMS_HOME>/bin>

Resecure Management Agents.

Resecure all management agents point to this OMS using new OMS hostname .

<AGENT_INST>/bin/emctl secure agent -emdWalletSrcUrl https://<NEW_OMS HOST_NAME.DOMAIN NAME>:<UPLOAD_PORT>/em

Remove stale OMS entries.
The repository will be having the old OMS information which should be cleaned up.

To get the stale OMS entries cleaned, follow the My Oracle Support Doc Id 2764682.1 - How To Cleanup the Old OMS Entries in the Repository DB That are Leftover After OMS Migration Activity.
Migrate additional OMSs.

If you want to migrate additional OMSs then decommission additional OMSs once the primary OMS migration was successful.

It's recommended to reinstall/reconfigure the additional OMSs using the regular Add OMS deployment procedure or the Silent method to install additional OMS.