RAID is a storage technology that distributes data across multiple physical drives to act as a single logical unit. It addresses the limitations of individual disks regarding I/O performance and hardware reliability by introducing redundancy and parallel data access.
How it works
The system operates using three core techniques: striping, which spreads data across drives to increase throughput; mirroring, which copies data for redundancy; and parity, which uses mathematical calculations to reconstruct lost data. Implementation can be hardware-based via a controller or software-based within the OS.
RAID 0: High performance through striping, no data protection.RAID 1: Mirroring for 100% data redundancy.RAID 5: Block-level striping with distributed parity.RAID 10: A stripe of mirrors, providing high speed and fault tolerance.
RAID is standard in enterprise servers and NAS devices. For instance, a RAID 10 configuration requires at least four disks and can survive the failure of multiple drives (one in each mirror set), maintaining system uptime in environments where downtime costs are high.