first version of the knowledge base :)

30 - Systems/homelab/backup-architecture.md

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+---
+title: Backup Architecture
+description: Reference backup architecture for self-hosted services, data, and infrastructure components
+tags:
+  - backup
+  - architecture
+  - self-hosting
+category: systems
+created: 2026-03-14
+updated: 2026-03-14
+---
+
+# Backup Architecture
+
+## Summary
+
+A backup architecture defines what is protected, where copies live, and how recovery is validated. In self-hosted environments, the architecture must account for application data, infrastructure configuration, and the operational steps needed to restore service safely.
+
+## Why it matters
+
+Many backup failures are architectural rather than tool-specific. Storing copies on the wrong system, skipping configuration, or never testing restores can make an otherwise successful backup job useless during an incident.
+
+## Core concepts
+
+- Multiple copies across different failure domains
+- Separation of live storage, backup storage, and off-site retention
+- Consistent backups for databases and stateful services
+- Restore validation as part of the architecture
+
+## Practical usage
+
+A practical backup architecture usually includes:
+
+- Host or VM backups for infrastructure nodes
+- File or repository backups for application data
+- Separate backup of configuration, Compose files, and DNS or proxy settings
+- Off-site encrypted copy of critical repositories
+
+Example model:
+
+```text
+Primary workloads -> Local backup repository -> Off-site encrypted copy
+Infrastructure config -> Git + encrypted secret store -> off-site mirror
+```
+
+## Best practices
+
+- Back up both data and the metadata needed to use it
+- Keep at least one copy outside the main site or storage domain
+- Use backup tooling that supports verification and restore inspection
+- Make restore order and dependency assumptions explicit
+
+## Pitfalls
+
+- Treating snapshots as the only backup mechanism
+- Backing up encrypted data without preserving key recovery paths
+- Assuming application consistency without database-aware handling
+- Skipping restore drills for high-value services
+
+## References
+
+- [restic documentation](https://restic.readthedocs.io/en/latest/)
+- [BorgBackup documentation](https://borgbackup.readthedocs.io/en/stable/)
+- [Proxmox VE Backup and Restore](https://pve.proxmox.com/pve-docs/chapter-vzdump.html)