What is RAID (Redundant Array of Independent Disks; a.k.a. Redundant Array of Inexpensive Disks)?
RAID (Redundant Array of Independent Disks; a.k.a. Redundant Array of Inexpensive Disks) is a computer data storage technology that combines multiple disk drive components into a logical unit, which is accessed by the operating system. The basic idea is to use redundancy to offset the increased failure rate of spreading storage across many disks.
Data storage is distributed across the respective drives in one of several methods called “RAID levels”, depending on the different schemes or architectures that are required. Each design has its own risk mitigation, capacity and performance.
RAID-1: This type is also known as disk mirroring and consists of at least two drives that duplicate the storage of data. There is no striping. Read performance is improved since either disk can be read at the same time. Write performance is the same as for single disk storage. RAID-1 provides the best performance and the best fault-tolerance in a multi-user system.
RAID-1 is the array of choice for performance-critical, fault-tolerant environments. The basic idea is to use redundancy to offset the increased failure rate of spreading storage across many disks.
o Reading and writing of data are much faster – fetch data in parallel.
o Higher reliability – if disk fails, just make copy of the other disk to generate mirror.