What version of RAID protects data against loss of any one disk by adding an extra disk to store dedicated parity information?

The correct response involves understanding the function of RAID configurations concerning data protection and redundancy. RAID 5 is specifically designed to protect against the loss of any single disk by implementing a parity-based approach. In this configuration, the data is distributed across multiple disks along with parity information, which allows the system to reconstruct the lost data if one disk fails.

The parity information is calculated based on the data in the other disks, and it is spread across all the disks in the array, effectively utilizing the additional disk space to enhance redundancy without sacrificing a large portion of storage capacity. This strategy not only provides fault tolerance but also allows for efficient use of storage when compared to mirroring data, as seen in other RAID levels.

In contrast, RAID 3 and RAID 4 use a dedicated disk for parity as well, but they typically handle data differently, often being considered less flexible than RAID 5. RAID 1+0 combines mirroring and striping, offering a different approach to redundancy that protects against multiple disk failures but does not utilize a dedicated parity disk. RAID 6 improves upon RAID 5 by allowing for the failure of two disks, leveraging multiple parity blocks for greater data protection, but the question specifically focuses on the single disk scenario which aligns with RAID