RAID Levels - TarisMajor/5143-OpSystems GitHub Wiki
RAID (Redundant Array of Independent Disks) is a data storage technology that combines multiple physical disk drives into a single logical unit to improve performance, reliability, and storage capacity. Different RAID levels offer various advantages and trade-offs between these factors.
Key RAID Levels
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RAID 0 (Striping)
- Description: Data is split into blocks and distributed (striped) across all the disks in the array. This level offers no redundancy.
- Advantages: High read/write performance as data is read/written simultaneously across multiple disks.
- Disadvantages: No data protection; if one disk fails, all data is lost.
- Use Cases: Suitable for applications requiring high performance but not critical for data integrity, such as temporary storage or non-critical systems.
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RAID 1 (Mirroring)
- Description: Data is duplicated (mirrored) across two disks. Each disk contains an exact copy of the data.
- Advantages: High reliability and data protection. If one disk fails, data is still available on the other disk.
- Disadvantages: Storage capacity is halved as data is duplicated. Write performance can be slower.
- Use Cases: Ideal for critical systems where data integrity is paramount, such as databases and transactional systems.
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RAID 5 (Striping with Parity)
- Description: Data is striped across multiple disks with parity information distributed among the disks. Parity allows for data recovery in case of a single disk failure.
- Advantages: Good balance between performance, storage efficiency, and data protection. Can recover from a single disk failure without data loss.
- Disadvantages: Write performance can be slower due to the need to calculate and write parity. More complex to implement.
- Use Cases: Commonly used in business environments for file and application servers requiring a good balance of performance and reliability.
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RAID 6 (Striping with Double Parity)
- Description: Similar to RAID 5 but with two parity blocks, allowing for the recovery of data even if two disks fail simultaneously.
- Advantages: High data protection with the ability to recover from two simultaneous disk failures.
- Disadvantages: Lower write performance due to double parity calculations. More storage overhead compared to RAID 5.
- Use Cases: Suitable for environments where data availability and protection are critical, such as large data storage systems and backup servers.
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RAID 10 (Striping and Mirroring)
- Description: Combines RAID 0 and RAID 1 by striping data across mirrored pairs of disks. Requires a minimum of four disks.
- Advantages: High performance with excellent data protection. Faster rebuild times compared to other RAID levels.
- Disadvantages: High storage overhead as it requires doubling the number of disks for mirroring. More expensive to implement.
- Use Cases: Ideal for high-performance applications requiring robust data protection, such as transactional databases and critical application servers.