What happens if a DC with a FSMO role fails?

When a Domain Controller (DC) that holds a Flexible Single Master Operation (FSMO) role fails, the operation of the remaining DCs in the domain generally continues without immediate disruption. This is because the other DCs are still able to operate and handle most of the authentication and directory service functions.

However, certain specific tasks that rely on the FSMO role held by the failed DC cannot be performed until that role is either restored or transferred to another DC. These tasks include operations like schema updates, managing domain naming, or specific infrastructure needs, which may indeed require administrative intervention. Administrators may need to manually seize the FSMO roles if the DC is deemed irrecoverable, ensuring that the domain's functionality is maintained without prolonged interruptions.

It's important to understand that while the overall service is maintained, specific functionalities might be impeded, highlighting the necessity for having a well-planned recovery and redundancy strategy in place for FSMO roles. Other choices suggest outcomes that are more severe than what typically occurs with a FSMO role failure, such as complete cessation of all DC operations or major accessibility issues.