What is RAID
I. Overview of RAID Technology
RAID (Redundant Array of Independent Disks) is a technology that implements distributed data storage by combining multiple physical hard disks in a specific manner. Its core objective is to find the optimal solution among improving storage performance (such as read and write speed), enhancing data reliability (such as fault tolerance), or striking a balance between the two, and it is widely used in scenarios such as NAS (Network-Attached Storage). The following is an analysis of the technical features and applicable scenarios of various RAIDs.
II. RAID Technical Parameters and Applicable Scenarios Table
| RAID level | Minimum number of hard disks | Core Principles | Performance Characteristics | Fault Tolerance | capacity utilization rate | Applicable Scenarios |
|---|---|---|---|---|---|---|
| BASIC | 1 piece | Each hard drive is used independently, delivering the highest space utilization rate | Single-drive performance | no fault tolerance capability | 100%(Total capacity = sum of the capacities of all hard disks) | Suitable for users with low data security requirements or those who have multiple backup solutions in place, but who wish to switch to RAID 1 mode later |
| JBOD | 1 piece | Multiple hard drives are sequentially concatenated into a single logical volume, which offers no redundancy protection but features flexible space utilization. | The performance is close to that of a single hard disk, and the read and write speed will not be significantly improved | It has no fault tolerance, and the failure of a single hard disk will lead to the complete loss of all data | 100%(Total capacity = sum of the capacities of all hard disks) | Suitable for users with low requirements for data security or those who have multiple backup solutions in place |
| RAID 0 | 2 pieces | Data striping distributes data by splitting it into segments and writing them in parallel to multiple hard drives, with no redundancy. | The read-write speed increases linearly with the number of hard disks (theoretical value), delivering optimal performance | It has no fault tolerance, and the failure of a single hard disk will lead to the complete loss of all data | 100%(Total capacity = sum of the capacities of all hard disks) | Scenarios with extremely high performance requirements and tolerable data loss (such as temporary caching, real-time storage of video editing creatives) |
| RAID 1 | 2 pieces | Data mirroring: all data is written to two hard disks simultaneously to keep them completely consistent | The read performance is close to that of a single hard disk (supports parallel reading), while the write performance is equivalent to that of a single hard disk (requires dual writing) | It supports single hard disk failure, and data can be recovered from the mirror disk | 50%(total capacity = capacity of a single hard disk, taking the capacity of the smallest disk) | Scenarios with extremely high requirements for data security (such as the storage of important documents and critical business data) |
| RAID 5 | 3 pieces | Block-level striping, with parity information distributed across all hard drives and no dedicated parity drive | Its read and write performance outperforms a single drive (thanks to multi-drive parallelism), while its write performance is slightly lower than that of RAID 0. | Supports single-drive failure recovery, with performance degradation during rebuilding | (Total capacity - capacity of one hard drive) | General scenarios that balance performance, reliability and cost (such as home NAS, file storage for small and medium-sized enterprises) |
| RAID 10 | 4 pieces (even number) | First, group the hard disks into pairs to form RAID 1 (mirror), then integrate these mirror groups via RAID 0 (striping) | Its read-write performance is close to that of RAID 0, while featuring the reliability of RAID 1 | Each group of mirrors supports one faulty hard drive per group (a maximum of 2 hard drive failures are allowed, which must belong to different mirror groups) | 50%(total capacity = number of mirror groups × capacity of a single hard drive) | Scenarios that place high demands on both performance and security (such as small database servers and important data storage with frequent read and write operations) |
III. RAID Types Supported by Tieniu AiNAS
| Device Model | Supported RAID types |
|---|---|
| Zero 1 pro | BASIC/JBOD/RAID 0 /RAID 1 /RAID 5 /RAID 10 |
IV. Differences Between JBOD and RAID 0
**JBOD **and **RAID 0 **can both combine the space of multiple hard drives into a single unit to improve storage utilization, but there are significant differences between the two in terms of data organization, performance and fault tolerance.
| JBOD | RAID 0 | |
|---|---|---|
| Definition | Concatenate multiple hard drives sequentially into a single logical volume, and write data to each hard drive in turn | Distribute data to multiple hard drives for parallel read and write operations |
| Performance | The performance is close to that of a single hard disk, and the read and write speed will not be significantly improved | It significantly improves read and write performance through parallel writing, and is especially faster when processing large files |
| Scalability | Hard disk capacity can be flexibly expanded, and the expansion is supported without losing the existing data in the storage pool | Hard disk capacity can be flexibly expanded, and the expansion is supported without losing the existing data in the storage pool |
V. Conclusion
The choice of RAID technology should be based on the business's requirements for performance, reliability, and cost: RAID 0 aims for the Highest performance but no fault tolerance; RAID 1 trades capacity for security; RAID 5 is the preferred balanced type; RAID 10 balances high performance and reliability, suitable for critical scenarios. If you only have one disk at hand, it is recommended to prioritize BASIC mode for future compatibility considerations.