What does raid mean, what is the raid card?

What does raid mean? Raid is the abbreviation of English Redundant Array of Independent Disks. In Chinese, it is a redundant array of independent disks, or simply a disk array. Simply put, Raid is a combination of multiple independent hard disks (physical hard disks) in different ways to form a disk group (logical hard disk), which provides higher storage performance and data redundancy than a single hard disk. The different ways of composing a disk array become Raid Levels.

Raid technology through continuous development, now has a basic level of Raid from Raid0 to Raid6 seven kinds. In addition, there are some basic Raid level combinations, such as Raid10 (a combination of Raid0 and Raid1), Raid50 (a combination of Raid0 and Raid5), and so on. Different Raid levels represent different storage performance, data security, and storage costs.

The function of data redundancy is to use the redundant information to recover the damaged data after the user data is damaged, thus ensuring the security of the user data. In the user's view, the composed disk group is like a hard disk, the user can partition it, format it and so on. In summary, the operation of the disk array is exactly the same as a single hard disk. The difference is that disk arrays have much higher storage performance than a single hard disk and can provide data redundancy.

What is a raid card?

Raid cards are boards that implement Raid functionality, usually consisting of a series of components such as I/O processors, SCSI controllers, SCSI connectors, and caches. Different Raid cards support different Raid functions. Supports Raid0, Raid1, Raid3, Raid4, Raid5, Raid10. Raid cards allow many disk drives to simultaneously transfer data, and these disk drives are logically a disk drive, so using Raid can achieve several times, tens of times, or even hundreds of times the speed of a single disk drive. This is also the problem that the Raid card originally intended to solve. Fault tolerance is available, which is the second important feature of the Raid card.