Which RAID level features requires at least four drives?

RAID Level 10, also known as RAID 1+0, requires a minimum of four drives to implement. This level combines the features of both RAID 1 and RAID 0. It mirrors data for redundancy (RAID 1) while also striping the data across multiple drives for improved performance (RAID 0).

To form a RAID 10 array, you need at least two sets of mirrored drives. Each set requires two drives for mirroring, which means that to create a functioning RAID 10 configuration, you must have at least four drives in total. This setup not only provides protection against drive failure but also enhances read and write speeds due to the data striping feature, making it a popular choice in environments where both performance and redundancy are critical.