Glossary - R

RAID

(Redundant Array of Inexpensive/Independent Disks) is a method of saving data on storage media. It is used to speed up work with data, or ensure data security against hard drive failures. Security is ensured by a specific data saving on a number of independent disks thanks to which the stored data are maintained even after a failure of one of the disks. The security level differs depending on the type of RAID, which is designated by numbers (usually RAID 0, RAID 1, RAID 5, RAID 6). RAID is often used in servers, but it must be noted that the RAID does not replace data backup. Methods of data storage in RAID arrays continue to develop and evolve.

Reading and writing heads

are located within each hard drive. They ensure reading and writing of the data from the magnetic layer of hard drive data plate.

RLL

(Run Length Limited): is the line code used to transfer any data through a communication channel with a limited bandwidth. It is used in telecommunications and in systems for storing data, in which the media move in respect to the fixed recording head.

ROM

(Read-Only Memory) is a type of electronic memory that is read-only. This information is stored in the long-term and without the need for power. In case of disks, the information is stored in the ROM, which is closely linked to the service area.