What does combining multiple hard drives into a single unit with RAID primarily offer?

Combining multiple hard drives into a single unit using RAID (Redundant Array of Independent Disks) primarily offers fault tolerance against drive failure. This means that if one hard drive fails, the data remains accessible from the other drives in the array, thus preventing data loss. RAID achieves this by using various configurations—such as mirroring (RAID 1) or striping with parity (RAID 5)—which replicate or distribute data across multiple disks. This redundancy is crucial for maintaining data integrity and availability, especially in critical systems where uptime is essential.

While improving data access speed can be a benefit of certain RAID configurations, the primary purpose that defines RAID is its ability to protect against hardware failures. Enhanced data encryption is not a direct feature of RAID configurations, and while physical size may increase due to adding more drives, it’s not a primary characteristic or advantage of using RAID.