Disclaimer - The information below is not intended to be a scientific study on RAID and how it works. It is nonspecific and the actual way in which a RAID controller stores data may differ widely. This is a basic overview of the principles of RAID in order to allow people to decide whether RAID is right for them, and if so, which RAID type they should choose.
What is RAID (Redundant Array of Inexpensive Disks)?
RAID is a set of disks used together to improve the performance and reliability of a storage set. RAID can be used for striping, which increases the performance of drives, but risks reliability by using two separate disks to store a single file. It can also be used for mirroring, which increases reliability by replicating data to two or more drives, but increases cost. A fundamental understanding of this comes from the knowledge that data on disks are stored in the form of binary signals on a disk. We use ones and zeros when talking about binary data. A single text file could include the classic “Hello World”.