RAID 10 Explained

4 min readJun 13, 2023

RAID 10 Structure — Image by PITS Global Data Recovery Services

When you have a large amount of important data, you probably want to store it in a more secure and efficient way. The Redundant Array of Independent Disks (RAID) technology tries to solve this problem by providing a range of options to suit various business needs.

RAID 10, also known as RAID 1+0 or RAID level 10, is a popular choice for those who want a balance between performance, redundancy, and capacity.

In this blog, we will talk about what RAID 10 is and how it functions as a robust data storage solution.

What is RAID 10?

Image by PITS Global Data Recovery Services

RAID 10 treats multiple data storage devices (e.g., hard drives) as a single logical unit; it combines elements of RAID 1 (mirroring) and RAID 0 (striping) to provide the benefits of both redundancy and performance. It requires a minimum of four disks, with data being both mirrored and striped across the disks in the array.

RAID level 10 is well-suited for mission-critical environments such as databases, virtualization platforms, and high-performance computing, where high-speed data access, fault tolerance, and rapid data recovery are essential. The combination of mirroring and striping in RAID 10 provides excellent read and write performance, while the mirroring ensures data redundancy and the ability to withstand multiple drive failures without data loss.

Structure

In a RAID 10 array, the drives are usually divided into pairs, and each pair is mirrored. This means that for every data block written to one drive, an identical block is written to its mirror drive. Once the mirroring is complete, the data is then striped across the mirrored pairs. This striping enables concurrent read and write operations, resulting in improved performance compared to a single disk.

Redundancy and Fault Tolerance

The mirroring feature of RAID 10 ensures redundancy and fault tolerance. If one drive fails, the mirrored drive still contains an exact copy of the data, allowing for continued access and uninterrupted operation. The array can sustain the failure of a single drive in each mirrored pair without data loss.

Performance and Capacity

RAID 10 is also good in terms of performance, particularly for applications that involve heavy read and write operations. With the data striped across the mirrored pairs, read and write operations can be performed in parallel, enhancing performance. Additionally, since data is mirrored, read operations can be serviced by any drive in the mirrored pair, further improving read performance.

In terms of capacity, RAID 10 provides effective utilization. The total usable capacity of a RAID 10 array is the sum of all the capacities of RAID 1s in the array.

For example, in a RAID 10 array with four 1 TB drives (4 x 1 TB), the usable capacity would be 2 TB. This reduction in capacity is due to the mirroring feature, where each block of data is duplicated on a mirrored drive.

Pros of RAID 10

Excellent performance for both read and write operations, especially for applications with high I/O demands.
Robust fault tolerance and data redundancy, with the ability to withstand the failure of multiple drives as long as they are not part of the same mirrored pair.
Fast rebuild times in the event of a drive failure, as data can be copied directly from the mirrored drive.

Cons of RAID 10

Requires a larger number of drives compared to other RAID configurations, which can increase costs.
Reduced usable capacity due to the mirroring requirement, as data is duplicated on mirrored drives.
Limited scalability.

Conclusion

RAID 10, as we mentioned today, is a modern data storage solution that offers a balance between performance, redundancy, and capacity. By combining mirroring and striping, RAID 10 provides both data protection and improved performance for demanding applications. The ability to withstand the failure of multiple drives, rapid rebuild times, and efficient read and write operations make RAID 10 an attractive choice for businesses and organizations with critical data storage needs. However, the higher drive requirement and reduced usable capacity should be carefully considered. With proper planning and implementation, RAID 10 can provide a reliable and high-performance storage solution for a variety of applications.