RAID coordinates multiple storage devices so that they operate as an array rather than as isolated disks. This lesson introduces RAID’s purpose, key ideas, and historical origins.
RAID stands for Redundant Array of Independent Disks. A RAID system distributes or duplicates data across two or more secondary storage devices, such as hard disk drives (HDDs) or solid-state drives (SSDs). The operating system may see the devices as one logical storage volume, even though data is physically stored across several drives.
All flashcards
What is RAID?
RAID is an approach that coordinates two or more storage devices, distributing or duplicating data among them according to a chosen RAID level.
What is data striping?
Striping divides data into pieces and distributes them across drives, enabling parallel access. By itself, it does not provide redundancy.
What is mirroring?
Mirroring stores identical copies of data on multiple drives so that a remaining copy may be used if a drive fails.
What is parity in RAID?
Parity is calculated recovery information stored with data. It can be used to reconstruct missing data after certain drive failures.
Who coined the term RAID, and when?
David Patterson, Garth Gibson, and Randy Katz coined the term at the University of California, Berkeley, in 1987.
Quiz questions
What can happen to a RAID 0 volume if one member drive fails?Answer: The entire volume can become inaccessible.
How many failed drives can RAID 6 tolerate?Answer: Up to two failed drives.
How does RAID 4 organize data and parity?Answer: Block-level striping with parity on a dedicated drive.
How is a RAID 10 array constructed?Answer: Drives are mirrored in pairs, then data is striped across those pairs.
What manages a hardware RAID array?Answer: A dedicated RAID controller.
Based on the Wikipedia article RAID, licensed CC BY-SA 4.0. Adapted into a summary, flashcards and quizzes.