Oracle Exam 1Z0-998-20 Topic 17 Question 8 Discussion

https://docs.cloud.oracle.com/en-us/iaas/Content/Database/Tasks/updatingDB.htm

OS Updates

Before you update the OS, review the following important guidelines and information:

* Back up your DB system's databases prior to attempting an OS update.

* Do not remove packages from a DB system. However, you might have to remove custom RPMs (packages that were installed after the system was provisioned) for the update to complete successfully.

Warning

Do not install NetworkManager on the DB system. Installing this package and rebooting the system results in severe loss of access to the system.

* Oracle recommends that you test any updates thoroughly before updating a production system.

* The image used to launch a DB system is updated regularly with the necessary patches. After you launch a DB system, you are responsible for applying the required OS security updates published through the Oracle public YUM server.

* To apply OS updates, the DB system's VCN must be configured to allow access to the YUM repository. For more information