What is meant by RAID in IT?

The abbreviation RAID stands for Redundant Array of Independent Disc, i.e. redundant arrangement of independent hard disks. So in a Redundant Array of Independent Disc system, multiple hard drives are bundled together into one physical drive. A RAID is mainly used in servers. The reason: By combining several hard drives, the read and write speed of the drive can be increased and the capacity can be increased.

RAID systems are divided into different levels. At least two hard drives are bundled in a RAID-0, which share the data among themselves. This allows the server’s controller to read data from one disk while it is still storing data on the other. This means that parallel processes are possible, which significantly increase the performance of a server. In a RAID-1, on the other hand, data redundancy is created that is otherwise deliberately avoided in computer systems: Here, too, at least two hard disks are coupled. However, the data is always duplicated, so that the server always has a backup copy. RAID-5 is a combination of optimized speed and data security. Although this is not an exact copy of the data, the controller can reconstruct the data if one of the disks in the Redundant Array of Independent Disc is lost. For a high read and write speed, processes run in parallel, as with RAID-0.

There are a total of seven different levels of Redundant Array of Independent Disc, of which only the three mentioned are used regularly. The coupling of several hard disks is used for two reasons: to manage the high data traffic in a server connected to a network and to secure sensitive data meant on a server. The servers from centron.de also work with a RAID.