Principles of RAID0, RAID1, RAID0 + 1, and RAID5

 

RAID 0, also known as Stripe or Striping, represents the highest storage performance in all RAID levels. RAID 0 improves storage performance by distributing continuous data to multiple disks for access. In this way, the system can execute data requests on multiple disks in parallel, each disk executes its own data request. This type of parallel operations on data can make full use of the bandwidth of the bus, significantly improving the overall disk access performance

RAID 1, also known as Mirror or repair ing, is designed to maximize the availability and maintainability of user data. RAID 1 automatically copies data written to the hard disk to another hard disk. RAID 1 provides the highest data security protection for all RAID levels. Likewise, because of the data is backed up, backup data accounts for half of the total storage space. Therefore, Mirror's disk space utilization is low and storage costs are high.

Although Mirror cannot improve storage performance, it is especially suitable for storing important data, such as server and database storage, due to its high data security.

RAID 5 is a storage solution that combines storage performance, data security, and storage costs. RAID 5 does not back up the stored data, but stores the data and the corresponding parity information on each disk that makes up RAID 5, in addition, the parity information and the corresponding data are stored on different disks. When a disk data in RAID 5 is damaged, the damaged data is restored using the remaining data and the corresponding parity information.

RAID 5 can be understood as a compromise between RAID 0 and RAID 1. RAID 5 can provide data security for the system, but it is more secure than Mirror, and the disk space utilization is higher than Mirror. RAID 5 has a Data Reading Speed similar to RAID 0, but has an additional parity information. The data writing speed is slightly slower than that of a single disk. At the same time, because multiple data correspond to one parity information, the disk space utilization of RAID 5 is higher than that of RAID 1, and the storage cost is relatively low.

RAID 0 + 1: RAID 0 + 1 is a combination of RAID 0 and RAID 1, also known as RAID 10.

RAID 0 + 1 is a solution that combines storage performance and data security. It provides the same data security as RAID 1, and the storage performance is similar to RAID 0.

RAID 0 + 1 also provides data security through 100% of data backups. Therefore, the disk space utilization of RAID 0 + 1 is the same as that of RAID 1, resulting in high storage costs.

The features of RAID 0 + 1 make RAID 0 + 1 particularly suitable for fields that require both massive data access and strict data security requirements, such as banking, finance, commercial supermarkets, warehouse storage, and various file management.

RAID is a structure that combines disk arrays and data bars to improve data availability. IBM started researching this technology as early as 1970. RAID can be divided into RAID Level 1 and RAID Level 6, which are usually called RAID 0, RAID 1, RAID 2, RAID 3, RAID 4, RAID 5, and RAID 6. Each RAID level has its own strengths and weaknesses. "parity" is defined as the redundant information of user data. When the hard disk fails, data can be generated again.

RAID 0: RAID 0 is not a real RAID structure and has no data redundancy. RAID 0 continuously splits data and concurrently reads/writes data on multiple disks. Therefore, it has a high data transmission rate. However, RAID 0 does not provide data reliability while improving performance. If a disk fails, the entire data will be affected. Therefore, RAID 0 cannot be used in key applications requiring high data availability.

RAID 1: RAID 1 achieves data redundancy through data mirroring and generates mutually backed up data on two pairs of separated disks. RAID 1 can improve read performance. When raw data is busy, data can be directly copied from the image. RAID 1 is the most expensive in the disk array, but provides the highest data availability. When a disk fails, the system can automatically switch to the image disk without restructuring the invalid data.

RAID 2: in terms of concept, RAID 2 is similar to RAID 3. Both of them are distributed in blocks on different hard disks, in bytes or bits. However, RAID 2 uses the encoding technology known as "increase average error correction code" to provide error detection and recovery. This encoding technology requires multiple disks to store inspection and recovery information, making RAID 2 more complicated. Therefore, it is rarely used in commercial environments.

RAID 3: Unlike RAID 2, RAID 3 uses a single disk to store parity information. If a disk becomes invalid, data can be regenerated on the parity disk and other data disks. If the parity disk is invalid, data usage is not affected. RAID 3 provides a good transfer rate for a large amount of continuous data, but for random data, parity disks will become the bottleneck of write operations.

RAID 4: Like RAID 2 and RAID 3, RAID 4 and RAID 5 also block data and distribute data on different disks, but the disk unit is block or record. RAID 4 uses a disk as the parity disk. Each write operation requires access to the parity disk, which becomes the bottleneck of write operations. It is rarely used in commercial applications.

RAID 5: RAID 5 does not have a specified parity disk. Instead, it accesses data and parity information on all disks. On RAID5, read/write pointers can be performed on the array devices at the same time, providing higher data traffic. RAID 5 is more suitable for small data blocks and random read/write data. Compared with RAID 5, RAID 3 has an important difference in that each data transmission of RAID 3 involves all array disks. For RAID 5, most data transmission only operates on one disk and can be performed in parallel. There is a "Write loss" in RAID 5, that is, each write operation will generate four actual read/write operations, two of which read the old data and parity information, write new data and parity information twice.

RAID 6: Compared with RAID 5, RAID 6 adds the second independent parity information block. Two independent parity systems use different algorithms to ensure high data reliability. Even if the two disks are invalid at the same time, data usage will not be affected. However, you need to allocate more disk space to the parity check information, which is more "Write loss" than RAID 5 ". The Write Performance of RAID 6 is very poor. Poor performance and complex implementation make RAID 6 seldom used.

RAID 0, also known as Stripe or Striping, represents the highest storage performance in all RAID levels. RAID 0 improves storage performance by distributing continuous data to multiple disks for access. In this way, the system can execute data requests on multiple disks in parallel, each disk executes its own data request. This type of parallel operations on data can make full use of the bandwidth of the bus, significantly improving the overall disk access performance

RAID 1, also known as Mirror or repair ing, is designed to maximize the availability and maintainability of user data. RAID 1 automatically copies data written to the hard disk to another hard disk. RAID 1 provides the highest data security protection for all RAID levels. Likewise, because of the data is backed up, backup data accounts for half of the total storage space. Therefore, Mirror's disk space utilization is low and storage costs are high.

Although Mirror cannot improve storage performance, it is especially suitable for storing important data, such as server and database storage, due to its high data security.

RAID 5 is a storage solution that combines storage performance, data security, and storage costs. RAID 5 does not back up the stored data, but stores the data and the corresponding parity information on each disk that makes up RAID 5, in addition, the parity information and the corresponding data are stored on different disks. When a disk data in RAID 5 is damaged, the damaged data is restored using the remaining data and the corresponding parity information.

RAID 5 can be understood as a compromise between RAID 0 and RAID 1. RAID 5 can provide data security for the system, but it is more secure than Mirror, and the disk space utilization is higher than Mirror. RAID 5 has a Data Reading Speed similar to RAID 0, but has an additional parity information. The data writing speed is slightly slower than that of a single disk. At the same time, because multiple data correspond to one parity information, the disk space utilization of RAID 5 is higher than that of RAID 1, and the storage cost is relatively low.

RAID 0 + 1: RAID 0 + 1 is a combination of RAID 0 and RAID 1, also known as RAID 10.

RAID 0 + 1 is a solution that combines storage performance and data security. It provides the same data security as RAID 1, and the storage performance is similar to RAID 0.

RAID 0 + 1 also provides data security through 100% of data backups. Therefore, the disk space utilization of RAID 0 + 1 is the same as that of RAID 1, resulting in high storage costs.

The features of RAID 0 + 1 make RAID 0 + 1 particularly suitable for fields that require both massive data access and strict data security requirements, such as banking, finance, commercial supermarkets, warehouse storage, and various file management.

RAID is a structure that combines disk arrays and data bars to improve data availability. IBM started researching this technology in 1970. RAID can be divided into RAID level 1 to RAID Level 6. RAID 0, RAID 1, RAID 2, RAID 3, RAID 4, RAID 5, RAID6. each RAID level has its own strengths and weaknesses. "parity" is defined as the redundant information of user data. When the hard disk fails, data can be generated again.

RAID 0: RAID 0 is not a real RAID structure and has no data redundancy. RAID 0 continuously splits data and concurrently reads/writes data on multiple disks. therefore, it has a high data transmission rate. however, RAID 0 does not provide data reliability while improving performance. If a disk fails, the entire data is affected. therefore, RAID 0 cannot be used in key applications that require high data availability.

RAID 1: RAID 1 achieves data redundancy through data mirroring and generates mutually backed up data on two pairs of separated disks. RAID 1 can improve read performance. When raw data is busy, data can be directly copied from the image. RAID 1 is the most expensive in the disk array, but provides the highest data availability. when a disk fails, the system can automatically switch to the image disk without restructuring the invalid data.

RAID 2: in terms of concept, RAID 2 is similar to RAID 3. Both of them are distributed in blocks on different hard disks, in bytes or bits. However, RAID 2 uses the encoding technology known as "increase average error correction code" to provide error detection and recovery. This encoding technology requires multiple disks to store inspection and recovery information, making RAID 2 more complicated. Therefore, it is rarely used in commercial environments.

RAID 3: Unlike RAID 2, RAID 3 uses a single disk to store parity information. If a disk becomes invalid, data can be regenerated on the parity disk and other data disks. If the parity disk fails, the data usage will not be affected. RAID 3 provides a good transmission rate for a large number of continuous data, but for random data, the parity disk will become a bottleneck for write operations.

RAID 4: Like RAID 2 and RAID 3, RAID 4 and RAID 5 also block data and distribute data on different disks, but the disk unit is block or record. RAID 4 uses a disk as the parity disk. Each write operation requires access to the parity disk, which becomes the bottleneck of write operations. It is rarely used in commercial applications.

RAID 5: RAID 5 does not have a specified parity disk. Instead, it accesses data and parity information on all disks. On RAID5, read/write pointers can be performed on the array devices at the same time, providing higher data traffic. RAID 5 is more suitable for small data blocks and random read/write data. An important difference between RAID 3 and RAID 5 is that each data transmission of RAID 3 involves all array disks. For RAID 5, most data transmission only operates on one disk and can be performed in parallel. There is a "Write loss" in RAID 5, that is, each write operation will generate four actual read/write operations, two of which read the old data and parity information, write new data and parity information twice.

RAID 6: Compared with RAID 5, RAID 6 adds the second independent parity information block. Two independent parity systems use different algorithms to ensure high data reliability. Even if the two disks are invalid at the same time, data usage will not be affected. However, you need to allocate more disk space to the parity check information, which is more "Write loss" than RAID 5 ". RAID 6 has very poor write performance. Poor performance and complex implementation make RAID 6 rarely used.