Applying Linux OS Security Patches

You can apply Linux OS security patches to compute nodes hosting Oracle Database Classic Cloud Service database deployments. How you apply OS patches depends on the database type used to create the database deployment:

Single Instance

You can apply OS patches to the compute node for a deployment hosting a single-instance database by using the dbaascli utility, or you can manually apply OS patches.

To apply OS patches by using the dbaascli utility, see Using the dbaascli Utility on Deployments Hosting a Single-Instance Database.
To manually apply OS patches, follow the instructions in Manually Applying Linux OS Security Patches.

Database Clustering with RAC

You manually apply OS patches to the two compute nodes for a deployment hosting an Oracle RAC database. For each compute node, follow the instructions in Manually Applying Linux OS Security Patches.

Single Instance with Data Guard Standby

You can apply OS patches to the two compute nodes for a deployment hosting an Oracle Data Guard configuration of single-instance databases by using the dbaascli utility, or you can manually apply OS patches.

To apply OS patches by using the dbaascli utility, see Using the dbaascli Utility on Deployments Hosting an Oracle Data Guard Configuration of Single-Instance Databases.
To manually apply OS patches:
1. For the compute node associated with the standby database, follow the instructions in Manually Applying Linux OS Security Patches.
2. After the compute node and standby database have rebooted, allow a few minutes for redo data to be applied to the standby database.
  
  To monitor the progress, connect as the opc user to the standby compute node, and run the following command:
```
$ dgmgrl show configuration verbose;
```
  The operation is complete when the preceding command returns no errors.
3. Perform a switchover from the primary database to the standby database in your Oracle Data Guard configuration. See Performing a Switchover Operation.
4. For the compute node associated with the new standby database (this was the primary database before you performed the switchover), follow the instructions in Manually Applying Linux OS Security Patches.
5. After the compute node and new standby database have rebooted, allow a few minutes for redo data to be applied to the new standby database.
  
  To monitor the progress, connect as the opc user to the new standby compute node, and run the following command:
```
$ dgmgrl show configuration verbose;
```
  The operation is complete when the preceding command returns no errors.
6. Perform a switchover back to the original primary database in your Oracle Data Guard configuration. See Performing a Switchover Operation.

Database Clustering with RAC and Data Guard Standby

You manually apply patches to the four compute nodes for a deployment hosting an Oracle Data Guard configuration of Oracle RAC databases:

For each of the two compute nodes associated with the standby RAC database, follow the instructions in Manually Applying Linux OS Security Patches.
After the compute nodes and standby RAC database have rebooted, allow a few minutes for redo data to be applied to the standby RAC database.

To monitor the progress, connect as the opc user to one of the standby RAC database compute nodes, and run the following command:
```
$ dgmgrl show configuration verbose;
```
The operation is complete when the preceding command returns no errors.
Perform a switchover from the primary RAC database to the standby RAC database in your Oracle Data Guard configuration. See Performing a Switchover Operation.
For each of the two compute nodes associated with the new standby RAC database (this was the primary RAC database before you performed the switchover), follow the instructions in Manually Applying Linux OS Security Patches.
After the compute nodes and new standby RAC database have rebooted, allow a few minutes for redo data to be applied to the new standby RAC database.

To monitor the progress, connect as the opc user to one of the new standby RAC database compute nodes, and run the following command:
```
$ dgmgrl show configuration verbose;
```
The operation is complete when the preceding command returns no errors.
Perform a switchover back to the original primary RAC database in your Oracle Data Guard configuration. See Performing a Switchover Operation.

Data Guard Standby for Hybrid DR

To manually apply OS patches to the compute node for the cloud standby database in a Hybrid DR deployment, follow the instructions in Manually Applying Linux OS Security Patches.

For information on applying OS patches to the compute node for the on-premises primary database in a Hybrid DR deployment, refer to the documentation for the appropriate Oracle Database version.