A VM cluster Data Guard implementation requires two Exadata database VM Clusters, one containing the primary database and one containing the standby database.

To change the SYS password or rotate TDE keys, use OCI API.

When adding a node to a VM cluster, an instance of the Data Guard database is automatically created on the new node.

When removing a node from a VM cluster, the instance and it's metadata on the removing node is deleted automatically.

A switchover reverses the primary and standby database roles.

Each database continues to be part of the Data Guard group in its new role. A switchover ensures no data loss. You can use a switchover before you perform planned maintenance on the primary database. Performing planned maintenance on a Exadata database compute node with a Data Guard group is typically done by switching the primary to the standby role, performing maintenance on the standby, and then switching it back to the primary role.

A failover transitions the standby database into the primary role after the existing primary database fails or becomes unreachable.

A failover might result in some data loss when you use Maximum Performance protection mode.

Reinstates a database into the standby role in a Data Guard group.

You can use the reinstate command to return a failed database into service after correcting the cause of failure.

Learn to set up a Data Guard group between databases.

1. Open the navigation menu. Under Oracle Database, click Exadata Database Service on Cloud@Customer.

   VM Clusters is selected by default.

2. Select your Compartment.

   A list of VM Clusters is displayed for the chosen Compartment.

3. In the list of VM clusters, click the VM cluster that contains the database for which you want to assume the primary role, and then click the name of that database.
4. Under Resources, click Data Guard Associations.
5. Click Add standby.
6. On the Add standby page, configure your Data Guard group.
   • • Choose the Data Guard experience:
       • Use the new Data Guard group Resource With this option, your new Data Guard configuration will be created as a Data Guard group resource. This option with new APIs supports adding multiple standby databases and provides other enhancements. If you currently have automation that manages Data Guard operations using the existing Data Guard Association API, you can update your applications to use the new API to take advantage of these new capabilities.
       • Use the existing Data Guard Association Resource Choose this option if your automation for managing Data Guard operations relies on the existing Data Guard Association API. However, you will not be able to add multiple standby databases and will not get the enhancements provided by the new API.

   • Data Guard group details:
     • Select a Data Guard type, Active Data Guard or Data Guard, based on the Oracle Database software license type you have deployed. If you have deployed Oracle Database Enterprise Edition Extreme Performance (License Included), then you may choose either Data Guard or Active Data Guard. If you have deployed Bring Your Own License (BYOL) Oracle Database Enterprise Edition without the Active Data Guard option, then you would select Data Guard, which is the default.
       • Active Data Guard: Active Data Guard is a licensed option to the Oracle Database Enterprise Edition and enables advanced capabilities that extend the basic Data Guard functionality. These capabilities include Real-Time Query and DML Offload, Automatic Block Repair of physical data corruptions, Standby Block Change Tracking, Global Data Services, and Application Continuity.
       • Data Guard: Oracle Data Guard ensures high availability, data protection, and disaster recovery for enterprise data. Data Guard provides a comprehensive set of services that create, maintain, manage, and monitor one or more standby databases to enable production Oracle databases to survive disasters and data corruptions. Data Guard maintains these standby databases as transactionally consistent copies of the production database.

     • Protection mode: The protection mode used for this Data Guard group.

       Maximum Performance provides the highest level of data protection that is possible without affecting the performance of a primary database.

       Maximum Availability provides the highest level of protection of data with zero data loss synchronous transport without compromising the availability of the database.

     • Transport type: The redo transport type used for the Data Guard association between the primary and this standby database.

       • Async: Asynchronous transport mode used with Maximum Performance protection mode.
       • Sync: Synchronous transport mode used with Maximum Performance and Maximum Availability protection mode.

       Protection Mode and Transport Type: Rules for Standby Database Creation

       • Creating the first standby: You cannot modify the Protection Mode or Transport Type for the first standby database.
         • The default settings are:
           • Protection Mode: Max Performance
           • Transport Type: Async
       • Creating the second to Nth standby: You cannot modify the Protection Mode or Transport Type for any subsequent standby databases.
         • The Protection Mode is inherited from the first standby.
         • The default Transport Type is set to Async.
   • Select peer VM cluster: Specify the following values for the standby:
     • Peer Region: The primary and standby databases could be running on two different VM clusters on a shared ExaDB-C@C system or on two geographically separated ExaDB-C@C systems managed from the same or different Oracle Cloud Infrastructure regions.
     • Peer Exadata Cloud@Customer infrastructure: Select the Exadata Database Service on Cloud@Customer infrastructure where the standby database is located. Click the CHANGE COMPARTMENT hyperlink to choose a compartment.
     • Peer VM Cluster: Select the Exadata database compute node that contains the standby database. Click the CHANGE COMPARTMENT hyperlink to choose a compartment.
   • Choose Database Home: Select an existing Database Home or create one as applicable.
     • Select an existing Database Home: If one or more Database Homes already exist for the database version you have selected, then this option is selected by default. And, you will be presented with a list of Database Homes. Select a Database Home from the list.
       Note
       
       Although only Database homes of the same version and RU are listed, the homes displayed may have different one-off patches than the primary. Though acceptable to have different one-offs, the best practice is to have identical database homes between primary and standby.
     • Create a new Database Home: If no Database Homes exist for the database version you have selected, then this option is selected by default. You can create the new Database Home with the same DSI as the primary database, or choose a different image. Note that DSIs are not available across regions. A separate DSI must be created in the peer region using the same RU as the primary.
       1. Click Change Database Image to select a database software image for the new Database Home.
       2. In the resulting Browse Database Images, do the following:
          1. Select the compartment containing the database software image you want to use to create the new Database Home.
          2. Select the Oracle Database software version that the new Database Home will use, then choose an image from the list of available images for your selected software version.
          3. Click Select.
             Note
             
             If you are using the new Data Guard group resource, you must first create the database home before adding the standby database.
   • Configure standby database:
     • Provide a unique name for the database:
       Note
       
       You cannot modify the db_name, db_unique_name, and SID prefix after creating the database.

       Optionally, specify a unique name for the database. This attribute defines the value of the db_unique_name database parameter. The value is case insensitive. The db_unique_name must contain only the permitted characters.

       Review the following guidelines when selecting a database name:

       • maximum of 30 characters
       • can contain alphanumeric and underscore (_) characters
       • begin with an alphabetic character
       • unique across the fleet/tenancy

       If a unique name is not entered, then the db_unique_name defaults to the following format <db_name>_<3 char unique string>_<region-name>.

     • Database password: Enter the database admin password of the primary database in the Database password field. This same database admin password will be used for the standby.

       The admin password and the TDE password must be the same. If they are not, follow the instructions in Changing the Database Passwords to align them.

     • TDE wallet password: Enter the TDE wallet password.
   • (Optional) Select Show Advanced Options.
     • Provide the Oracle SID prefix: Optionally, specify the Oracle SID prefix for the database. The instance number is automatically appended to the SID prefix to become the instance_name database parameter. If not provided, then the SID prefix defaults to the first 12 characters of the db_unique_name.
       Review the following guidelines when selecting a database name:

       • maximum of 12 characters
       • contain only alphanumeric characters
       • begin with an alphabetic character
       • unique in the VM cluster
7. Click Add standby.

To view the role of each database in a Data Guard group in an Exadata VM Cluster, follow this procedure.

1. Open the navigation menu. Under Oracle Database, click Exadata Database Service on Cloud@Customer.
2. Choose your Compartment.
3. Click on the VM Cluster containing the databases you wish to view their roles in Data Guard associations.
4. In the Databases section under Resources, the role of each database in this VM Cluster is indicated in the Data Guard role column.

You can switch between Data Guard types based on the Oracle Database software license type you have deployed.

1. Open the navigation menu. Under Oracle Database, click Exadata Database Service on Cloud@Customer.

   VM Clusters is selected by default.

2. Choose your Compartment.

   A list of VM Clusters is displayed for the chosen Compartment.

3. In the list of VM clusters, click the VM cluster that contains the primary database you want to switch Data Guard type.
4. Click the name of the primary database.
5. Under Resources, click Data Guard group.

   A list of databases that are members of the Data Guard group is displayed with the Data Guard type you have chosen for each Data Guard group member.

6. To edit Data Guard group details, click the Actions icon (three dots), and then click Edit.

   Edit Data Guard group screen is displayed.

7. Do the following on the Edit Data Guard group screen.
   • Select an applicable Data Guard type.
   • Select the Protection mode.
     Note
     
     Select the Transport type.
   • Set the Database password.
   • Click Edit Data Guard to save the changes.

You can initiate a switchover operation on a standby database that is a member of the Data Guard group.

1. Open the navigation menu. Under Oracle Database, click Exadata Database Service on Cloud@Customer.

   VM Clusters is selected by default.

2. Choose your Compartment.

   A list of VM Clusters is displayed for the chosen Compartment.

3. In the list of VM clusters, click the VM cluster that contains the primary database you want to switch over.
4. Click the name of the primary database.
5. Under Resources, click Data Guard group.
6. Select the standby database in the Data Guard group on which you want to perform a switchover. Click the Actions icon (three dots), and then click Switchover.
7. In the Switchover database dialog box, enter the database admin password, and then click Switchover.

You can initiate a failover operation on a standby database that is a member of the Data Guard group.

1. Open the navigation menu. Under Oracle Database, click Exadata Database Service on Cloud@Customer.

   VM Clusters is selected by default.

2. Choose your Compartment.

   A list of VM Clusters is displayed for the chosen Compartment.

3. In the list of VM clusters, click the VM cluster that contains the primary database's peer standby you want to fail over to.
4. Click the name of the standby database.
5. Under Resources, click Data Guard group.
6. Select the standby database in the Data Guard group on which you want to perform a failover. Click the Actions icon (three dots), and then click Failover.
7. In the Failover database dialog box, enter the database admin password, and then click Failover.

After you fail over a primary database to its standby, the standby assumes the primary role and the old primary is identified as a disabled standby.

srvctl stop database -d db-unique-name -o abort

srvctl start database -d db-unique-name -o mount

1. Open the navigation menu. Under Oracle Database, click Exadata Database Service on Cloud@Customer.

   VM Clusters is selected by default.

2. Choose your Compartment.

   A list of VM Clusters is displayed for the chosen Compartment.

3. In the list of VM clusters, click the VM cluster that contains the primary database.
4. Click the name of the primary database.
5. Under Resources, click Data Guard group.

   You will see the database you want to reinstate listed.

6. Click the Actions icon (three dots), and then click Reinstate.
7. In the Reinstate database dialog box, enter the database admin password, and then click Reinstate.

On a VM cluster, you remove a Data Guard group by terminating all the standby databases.

1. Open the navigation menu. Under Oracle Database, click Exadata Database Service on Cloud@Customer.

   VM Clusters is selected by default.

2. Choose your Compartment.

   A list of VM Clusters is displayed for the chosen Compartment.

3. In the list of VM clusters, click the VM cluster that contains the standby database you want to terminate.
4. Click the name of the standby database.
5. For the standby database you want to terminate, click the Actions icon (three dots), and then click Terminate.
6. In the Terminate Database dialog box, enter the name of the database, and then click OK.