What technique is used in storage device virtualization to enhance data reliability?

In the context of storage device virtualization, data mirroring is a technique that directly enhances data reliability. It involves creating an exact copy of the data stored on one disk onto another disk. This redundancy ensures that if one disk fails, the data can still be accessed from the mirrored copy, thereby providing high availability and reliability.

While data striping can improve performance by spreading data across multiple disks (which can increase read and write speeds), it does not inherently enhance data reliability because if one disk fails, the data across all the striped disks can be at risk.

The indication that both data striping and mirroring are utilized collectively emphasizes that while striping can contribute to performance, mirroring is the primary technique that enhances data reliability. Therefore, the correct answer addresses the dual role in storage virtualization: mirroring for reliability, alongside striping's performance benefits. Data compression, which reduces the amount of storage space data takes, is unrelated to data reliability and does not play a direct role in ensuring the integrity or availability of the stored data.