Which type of disk redundancy options can be implemented for a SQL database deployment?

RAID, which stands for Redundant Array of Independent Disks, is a technology that combines multiple physical disk drives into one or more logical units for improved performance, redundancy, or both. In the context of a SQL database deployment, RAID is particularly critical because it provides data redundancy, enabling fault tolerance. By using RAID configurations such as RAID 1 (mirroring) or RAID 5 (striping with parity), system administrators can ensure that if one disk fails, the data is still accessible from the other disks. This is essential for maintaining the availability and integrity of a SQL database, which often handles critical and transactional data requiring high resilience against hardware failures.

Other options, while related to storage and data management, do not specifically provide redundancy in the same structured manner that RAID does. Multipathing refers to the technique of using multiple physical paths between the server and storage to improve redundancy and performance but does not directly provide disk-level redundancy like RAID. Masking is about restricting access to certain data in storage without addressing redundancy factors. Tiering involves distributing data across different storage types based on performance needs but doesn't necessarily incorporate redundancy directly. Thus, for enhancing SQL database deployment through disk redundancy, RAID is the most applicable solution.