Implement Soft RAID and LVM through RHEL5

Article Title: Use RHEL5 to implement soft RAID and LVM. Linux is a technology channel of the IT lab in China. Including desktop applications, Linux system management, kernel research, embedded systems, open-source, and other basic categories RAID is the abbreviation of Redundant Array of Inexpensive Disk, meaning cheap Redundant Disk arrays, it is a theoretical standard for the technical implementation of disk arrays. It aims to reduce errors and improve the performance and reliability of storage systems. Common levels include 0, 1, and 5.

◆ RAID 0

RAID 0 splits data into multiple disks without any redundant information. Data is split into blocks and distributed to the disk. This level is also regarded as a pure data shard. One or more disks are required to create RAID 0. That is to say, a single disk can be considered as a RAID 0 array. Unfortunately, data entries reduce data availability. If a disk error occurs, the entire array will be paralyzed.

Advantages: easy to implement, no capacity loss-All buckets are available

Disadvantage: no fault tolerance capability, a disk error causes loss of data in all Arrays

◆ RAID 1

RAID 1 is suitable for arrays with high performance requirements and fault tolerance. In addition, RAID 1 is the only option that supports Fault Tolerance in environments with only two disks.

RAID 1 must contain at least two (only two) hard disks. Therefore, RAID 1 is also called Mirroring. The so-called image means that the content of each two hard disks is identical, but only one hard disk is displayed for the operating system to facilitate management. It can be seen that RAID 1 completely backs up data, and its reliability is the highest. Of course, the data write time may be a little longer, but because the two mirror hard disks can read data at the same time, the data read is the same as the RAID 0. The total capacity of the disk array is N/2 hard disks in the RAID level. RAID 1 provides the highest information availability through data mirroring. In addition, if the array supports simultaneous reading of data and images, the performance of reading information will be improved.

Advantage: reading performance is higher than that of a single disk

Disadvantage: twice the storage space required

◆ RAID 5

RAID 5 is the best choice for multi-user environments with low data writing performance requirements. However, it requires at least three disks for execution.

RAID 5 is used to split data entries and generate redundancy for parity checks. However, it does not use a fixed hard disk to store parity values. All data and parity values are distributed across all hard disks.

◆Advantage: the highest read rate and cost effectiveness of information processing-only one additional disk is required
◆Disadvantage: the transfer of independent information blocks is the same as that of a single disk and requires specific hardware.

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