RAID (Disk Array)
Redundant Array of Independent Disks
A system that combines multiple disks into a single unit to protect data and improve speed.
In Simple Terms
RAID is a technology that combines multiple hard disks or SSDs to use them as one large storage space. It can protect data from failure by writing the same content to multiple disks, or speed up reading and writing by splitting data into small pieces and writing them to multiple disks at the same time.
Behind the Name
RAID is an acronym for Redundant Array of Independent Disks. Redundant means "duplicated in case of failure," Array means "arrangement," and Independent means "independent." Taken literally, it means "a redundant array of independent disks," referring to the idea of duplicating data to protect against failure while combining multiple disks so they function as a single device.
Take a Closer Look!
RAID is a system that treats multiple disks as a single large storage destination, protecting data and increasing speed.
By combining separate disks together, it can achieve higher performance and reliability than a single disk could provide on its own.
Broadly speaking, there are different types such as RAID 0 and RAID 1, depending on how data is stored.
For example, RAID 0 is a method that splits data into small pieces and writes them to multiple disks at the same time.
This is called striping, and by dividing the work across multiple disks, it can dramatically increase read and write speed.
However, there is also a risk that if even one disk fails, all the data becomes unreadable.
RAID 1, on the other hand, is a method that writes exactly the same content to two disks at the same time.
This is called mirroring, and like a mirror, it constantly keeps the same data stored in two places.
Even if one disk fails, the data remains on the other, which helps prevent important data from being lost.
In addition, methods such as RAID 5 and RAID 6 write data in a distributed way while also storing recovery data called "parity."
Even if one disk fails (or two disks in the case of RAID 6), the original data can be calculated and restored using the remaining data and the parity, making this an efficient way to protect data.
RAID is a technology that is used especially often in corporate servers and backup devices that handle large amounts of data, more so than in personal computers.