ADR 007 - backup

Date

Restic / BorgBackup
- Also excellent deduplicating backup tools.
- However, Kopia provides a highly efficient native server mode (API) and cross-platform compatibility, making it easier to integrate with Synology DSM.

Physical Backup (Raw data folder backup / File system snapshots)
- Backing up the /var/lib/postgresql directory directly while the DB is running can lead to severe data corruption and inconsistency.
- Logical dumps (pg_dump) are much safer, database-agnostic, and easier to restore in a homelab environment.

All configuration files are managed by Git
- Configuration files are based on text
- It is necessary to version, history management.
- Local git -> private Gitea -> github private project (mirrored)
- This fulfills 3-2-1 backup rules
Data files are managed by Kopia and DSM
- Local storage - kopia -> DSM's Kopia repository server - CloudSync -> Cloud server such as OneDrive or Google Drive
- This fulfills 3-2-1 backup rules
Data files which needs backup
- DB data files: dump
  - DB data files are located on infra:/home/infra/containers/postgresql/backups/{cluster,$service}/
- App data files: Photos, Media, etc ..
  - App data files are located on app:/home/app/data/
- Backed up files: kopia
  - DSM:/kopia/{infra,app}/
Kopia over DSM configuration is managed by runbook with equivalent CLI commands due to vendor limitation
Restore will be processed manually
- DB data files
  - From kopia server to console:$HOMELAB_PATH/data/volume/infra/postgresql/{cluster,data}
- APP data files
  - From kopia server to APP vm after initiating before deploy services
Automative backup does not guarantee integrity of data system, so before reset the system conduct manual backup after making sure all services are shutdown.

All files including configuration and data back ups will fulfill 3-2-1 (3 Copies, 2 different media, 1 offsite) back up rules