Backup

A recoverable copy of data or system state retained separately from the active system.

Motivation

Backups protect against deletion, corruption, ransomware, failed changes, and infrastructure loss.

Important details

A backup is useful only when its restore process, retention, integrity, access control, and recovery objectives are tested.

Foundation guide

See SLI, SLO & SLA Foundations for a detailed explanation of service indicators, objectives, agreements, error budgets, metric categories, and production-style examples.