Backup & Disaster Recovery

Automated, multi-tier, encrypted where it matters, with off-site replication. Everything backs up to the NAS Host (ZFS); critical data also goes off-site.

Design principles

• Automate everything. Every backup runs on a schedule — cron or systemd timer. No manual steps required for normal operation.
• Encrypt sensitive data. Vaultwarden and Proxy Host backups are GPG-encrypted (AES-256 symmetric) before writing to NFS. Passphrase stored on the source host only, not in the repo.
• Retention with pruning. Application backups keep 7 daily + 4 weekly (Sunday promotion). VM images keep 2 weekly copies. Oldest copies are pruned only after the new backup succeeds.
• Off-site for irreplaceable data. Personal media and documents replicate to Backblaze B2 via Restic (AES-256 encrypted at rest).
• All backups land in one tree. The NAS Host has a unified backup root with per-service subdirectories.

VM image backups (weekly)

All four Hyper-V VMs on the Desktop Host are backed up as full VM images weekly:

• Method: Hyper-V Export-VM (native). Works on running VMs — auto-creates a checkpoint for consistency, exports the full VM, then removes the checkpoint. Brief pause (~seconds) during checkpoint creation; no downtime.
• Schedule: Weekly Saturday 02:00 AM via Task Scheduler. VMs exported sequentially to avoid saturating disk I/O and network.
• Target: NAS Host SMB share.
• Retention: 2 weekly copies per VM (~618 GB total with retention; ZFS compression reduces on-disk to ~214 GB).
• Network resilience: Robocopy /Z (restartable — resumes partial copies after interruption) + /J (unbuffered I/O). Per-VM retry loop (3 attempts) with SMB session re-establishment.
• Restore: Import-VM -Copy -GenerateNewId from the NAS share directly. Full VM (OS, packages, Docker images, crontabs, network config) restored in one operation.

Application data backups (nightly)

Sensitive service data is GPG-encrypted (AES-256) before writing to the NAS. Passphrases are stored on the source hosts only. Each backup script handles its own rotation — new backup writes first, then old copies beyond retention are pruned.

Off-site backup (Restic → Backblaze B2)

Personal media and documents from the NAS Host replicate off-site:

• Tool: Restic (deduplicating, encrypted backup program)
• Target: Backblaze B2 cloud storage
• Encryption: AES-256 at rest (Restic handles key management)
• What: Personal media library, documents archive
• Why: If the NAS Host suffers a catastrophic failure (e.g. house fire, multiple disk failures beyond RAIDZ1 tolerance), irreplaceable personal data survives off-site.

Backup tree layout (NAS Host)

All backups land in a single tree on the NAS Host with per-service subdirectories, separated by daily and weekly retention tiers.

Verification

• Audit scripts check backup recency: make audit-thorough flags any backup older than its expected threshold (e.g. >36 hours for nightly, >8 days for weekly).
• VM image backup logs both locally (Desktop Host) and remotely (NAS Host) for post-run inspection.
• GPG decryption tested periodically to confirm passphrases are correct and archives are intact.

What’s protected vs. what’s not

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