Backup and Disaster Recovery Design

This page explains the basics of planning backups and recovery as part of system design.

Why It Matters

Systems fail in different ways: accidental deletion, storage corruption, region outages, bad releases, or operator mistakes. Backup and recovery planning reduces downtime and data loss.

Core Concepts

• Backup frequency
• Retention period
• Recovery time objective (RTO)
• Recovery point objective (RPO)
• Restore testing

Basic Design Approach

1. Identify critical data and services.
2. Define acceptable downtime and data loss.
3. Choose backup frequency and storage location.
4. Document restore procedures.
5. Test recovery regularly.

Common Risks

• Backups exist but restores were never tested
• Backups stored in the same failure domain
• No one knows the real recovery steps
• Databases and application state are treated inconsistently

Practical Advice

• Test restore procedures regularly
• Keep backup ownership clear
• Store backups away from the primary failure domain
• Write recovery steps for the team, not just for one operator