What is RAID?

RAID (Redundant Array of Independent Disks) is a data storage virtualization technology that combines multiple physical disk drives into one logical unit. Its main purposes are to improve performance, increase fault tolerance, and enhance data protection. RAID configurations are commonly used in enterprise storage systems, network-attached storage (NAS), and distributed storage systems to safeguard against data loss while boosting speed.

RAID is especially valuable in environments where high availability and data redundancy are required, such as with distributed storage systems and NVMe over TCP setups.

How Does RAID Work?

RAID works by distributing data across multiple disks in different ways depending on the RAID level. These strategies involve striping (splitting data across disks), mirroring (duplicating data), and parity (using calculated values to rebuild data if a disk fails). RAID can be implemented in hardware, using a RAID controller, or software, through the operating system or dedicated software tools.

RAID 0 Explained

RAID 0, also known as striping, divides data evenly across two or more disks without redundancy. This setup maximizes performance by allowing simultaneous read and write operations. However, RAID 0 offers no data protection—if one disk fails, all data is lost.

Learn how I/O performance affects RAID configurations.

RAID 1 Explained

RAID 1 uses mirroring to duplicate data onto two or more disks. If one disk fails, the other still holds an exact copy, ensuring data availability. RAID 1 provides excellent redundancy but requires twice the storage capacity, which can make it expensive for large datasets.

Discover how RAID 5 works in tandem with open-source backup tools for complete protection.

RAID 5 Explained

RAID 5 offers a balance between redundancy and performance. It uses striping with parity, distributing data and parity information across at least three disks. If one disk fails, the system can reconstruct lost data from the parity and the remaining disks. RAID 5 is widely used for its storage efficiency and fault tolerance.

Explore how erasure coding offers an alternative to RAID 5.

RAID 10 Explained

RAID 10, also called RAID 1+0, combines the mirroring of RAID 1 and the striping of RAID 0. This hybrid solution requires at least four disks and offers high performance and redundancy. Data is mirrored and then striped, providing excellent fault tolerance and speed, but at the cost of 50% usable storage.

Check out scale-up vs. scale-out strategies to see how RAID 10 fits into scalable infrastructures.

Individual RAID Comparisons

To help clarify the strengths and trade-offs, here’s how each RAID level compares with others:

RAID 0 vs. RAID 1

RAID 0 emphasizes speed with no redundancy, making it faster than RAID 1 but far riskier. RAID 1, on the other hand, sacrifices half of the usable storage for full data duplication, prioritizing data safety over raw performance.

RAID 5 vs. RAID 1

RAID 5 is more storage-efficient than RAID 1, as it uses parity instead of full duplication. While RAID 1 handles disk failure more simply, RAID 5 provides better capacity usage, especially in arrays with more than three disks, but at the cost of more complex rebuild times after failure.

RAID 10 vs. RAID 5

RAID 10 delivers better write performance and faster rebuilds than RAID 5, though at the cost of 50% usable capacity. RAID 5 offers higher storage efficiency but can suffer from longer recovery times after a disk fails. For mission-critical workloads, RAID 10 is preferred; for maximizing storage while maintaining redundancy, RAID 5 is commonly used.

RAID 0 vs. RAID 10

RAID 0 is ideal when maximum performance is needed without concern for data loss, whereas RAID 10 offers almost the same speed benefits but adds robust redundancy. RAID 10 is the safer and more practical choice for important data that requires both speed and protection.

RAID Comparison Table

To better understand these RAID levels, here is a simple comparison:

Related Simplyblock Technologies and Tools

RAID is often integrated into modern distributed storage platforms like Simplyblock, which utilizes NVMe storage and erasure coding maximize reliability and performance. Learn how to get fast, reliable and future-proof storage with simplyblock.