RAID vs Backup: Technical guide for beginners

This technical guide provides an extensive strategic analysis of data resiliency, contrasting RAID (Redundant Array of Independent Disks) technology with modern backup strategies. It thoroughly explains RAID, including its core components like striping, mirroring, and parity, and details various RAID levels such as RAID 0, 1, 5, 6, and the enterprise-preferred RAID 10, highlighting the dangers of using RAID 5 with large disks due to rebuild risks. Crucially, the document stresses that RAID is not a backup, as it only offers high availability against hardware failure but provides zero protection against human error, corruption, or ransomware. Finally, it outlines essential backup methodologies (full, incremental, and differential) and defines the industry standard for comprehensive recovery as the 3-2-1-1-0 rule, which incorporates an air-gapped or immutable copy to specifically counter modern cyber threats.