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The editor will share with you what are the differences between raid1 and raid5. I hope you will gain a lot after reading this article. Let's discuss it together.

Differences: 1. Different security, RAID1 is higher than RAID5; 2, disk utilization is different, RAID5 is higher than RAID1; 3. RAID1 is suitable for scenarios with more read operations, while RAID5 is suitable for scenarios with more write operations.

Redundant Array of Independent disks (RAID,redundant array of independent disks) is a method of storing the same data in different places on multiple hard disks (therefore, redundantly). By placing data on multiple hard drives, input and output operations can overlap in a balanced manner to improve performance. Because multiple hard drives increase the mean time between failures (MTBF), storing redundant data also increases fault tolerance.

RAID 1

RAID 1 is called disk mirroring. the principle is to mirror the data from one disk to another, that is, when the data is written to one disk, it will generate an image file on another idle disk, so as to maximize the reliability and repairability of the system without affecting performance, as long as at least one disk in any pair of mirror disks in the system can be used. Even when half of the hard drives have problems, the system can run normally. When a hard disk fails, the system will ignore the hard disk and use the remaining mirror disk to read and write data, with good disk redundancy. Although this is absolutely safe for data, the cost will also increase significantly, with a disk utilization of 50%. For four hard drives with 80GB capacity, the available disk space is only 160GB. In addition, the RAID system with hard disk failure is no longer reliable, so the damaged hard disk should be replaced in time, otherwise the remaining mirror disk will also have a problem, then the whole system will crash. After the replacement of the new disk, the original data will take a long time to synchronize the mirror, and the external access to the data will not be affected, but the performance of the whole system will decline. Therefore, RAID 1 is often used in situations where critical and important data is saved.

RAID 1 mainly implements disk mirroring through secondary reads and writes, so the load on the disk controller is also quite heavy, especially in environments that need to write data frequently. In order to avoid performance bottlenecks, it is necessary to use multiple disk controllers.

RAID5

RAID5 (independent disk structure for distributed parity). As can be seen from its schematic diagram, its parity code exists on all disks, where p0 represents the parity value of band 0, and other meanings are the same. The reading efficiency of RAID5 is very high, the writing efficiency is average, and the block collective access efficiency is good. Because the parity codes are on different disks, the reliability is improved. However, it can not solve the parallelism of data transmission, and the design of the controller is also very difficult. The important difference between RAID 3 and RAID 5 is that every data transfer in RAID 3 involves all array disks. For RAID 5, most data transfers operate only on one disk and can be operated in parallel. There is a "write loss" in RAID 5, that is, each write operation produces four actual read / write operations, including two reads of old data and parity information, and two writes of new data and parity information.

The difference between RAID1 and RAID5

1. In terms of reading and writing: RAID1 read is no different from a single disk, while writing needs to be written on both sides. RAID5 has the best read performance, and the write performance is lower than that of writing to a single disk. Therefore, RAID1 is suitable for scenarios with many read operations, while RAID5 is suitable for scenarios with many write operations.

2. Security: RAID1 is higher than RAID5.

3. Disk utilization: RAID5 is higher than RAID1.

4. Cost: RAID1 is higher than RAID5.

5. Application: RAID1 is suitable for storing important data, and RAID5 is a scheme that takes into account storage performance, data security and storage cost.

After reading this article, I believe you have a certain understanding of the differences between raid1 and raid5. If you want to know more about it, welcome to follow the industry information channel. Thank you for your reading!

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