An administrator needs to roll back an Oracle patch on a database server VM using NDB. What is required for this action to be successful?

NDB (Nutanix Database Service) can only manage operations for which it has a complete history and metadata. To perform a rollback of a patch, NDB must have been the tool used to apply that patch initially. This allows NDB to know the pre-patch state and the exact changes made, enabling a clean and successful reversal. If the patch was applied manually or with another tool, NDB would be unaware of the operation and would not have the necessary information to orchestrate the rollback.

B. The database must be shut down. NDB's automated workflow handles the database state; shutting it down beforehand is not a required prerequisite for initiating the rollback action from the NDB UI.
C. The patch must have been applied on Grid home only using NDB. The requirement applies to both Oracle Home and Grid Home patching. Limiting the condition to only Grid Home is incorrect.
D. The database must be in read-only mode. A patch rollback is an intrusive operation that typically requires the database to be offline, not in read-only mode. NDB's workflow manages this state change.

1. Nutanix Database Service Administration Guide v4.2, Chapter: "Patching an Oracle Database", Section: "Patching an Oracle Database". The documentation outlines that patching operations, including pre-checks, application, and rollback, are managed within NDB. The ability to roll back is contingent on the patch being applied via NDB.