When upgrading to a newer operating system, what needs to be updated?

When upgrading to a newer operating system, updating the baseline is essential. A baseline refers to the established set of configurations, performance metrics, and operational parameters that define the normal state for a system. It serves as a reference point for future assessments and upgrades.

When an operating system upgrade is performed, it can introduce new features, security updates, and configurations that may alter performance characteristics or security postures. Consequently, it is necessary to revise the baseline to reflect these changes accurately. This updated baseline will help in monitoring the system's functionality and performance after the upgrade, ensuring that it meets the new standards and requirements.

The other options do not directly relate to the operational and configuration adjustments that occur with an operating system upgrade. An SLA, or Service Level Agreement, pertains to the level of service expected and does not specifically need updating during an OS upgrade. DNS, which stands for Domain Name System, is related to naming services and may not require changes with an OS upgrade. VPC, or Virtual Private Cloud, is more about networking and infrastructure setup rather than system operation. Thus, focusing on updating the baseline ensures that all operational aspects of the upgraded OS are adequately accounted for and monitored.