Which of the following is true regarding history block backups?

The statement regarding history block backups that is true is that manual intervention is required for some storage locations. In the context of AVEVA Historian or similar systems, history blocks can have various configurations and storage locations. Backing up can often depend on administrative settings or specific storage configurations that may not automatically include all blocks without user-defined processes or actions.

It is important to understand that while some blocks or storage locations might have automatic backup processes in place, others may need manual setting adjustments to ensure that backups occur successfully. This necessity for manual intervention is often due to system requirements, user preferences, or the need for specific configurations based on the organizational policy or data strategy.

For example, blocks that store historical data might require explicit instructions or settings to be defined by the user, especially if they are located on external servers or utilize specific protocols that do not have native automated backup functionalities. Thus, acknowledging the requirement for manual intervention in some cases underscores the need for operators to be proactive in managing their history backups to prevent data loss.