---
title: "Backup Strategy"
section: "infra"
tags: "infra"
parent: "/infra/"
description: "Layered 3-2-1 backup strategy covering NAS snapshots, offsite copies, and cloud storage."
layout: base.njk
---
<h1>Backup Strategy</h1>
<div class="detail-content">

<p>The homelab uses a layered backup approach, split into two independent
tracks: NAS user content, and Proxmox VM/LXC backups. Both follow a
3-2-1-style rule, multiple copies, multiple media types, at least one
copy on a different machine.</p>

<h2>NAS user content, four layers</h2>
<table>
<tr><th>Layer</th><th>Target</th><th>Frequency</th><th>Purpose</th></tr>
<tr><td>Snapshots</td><td>Synology, built-in</td><td>Hourly</td><td>Fast recovery of accidentally deleted files</td></tr>
<tr><td>Local backup</td><td>USB drive attached to the NAS</td><td>Daily</td><td>Local versioned backup, independent of the NAS disks</td></tr>
<tr><td>Offsite sync</td><td>External drive on a Raspberry Pi in a different room</td><td>Weekly</td><td>Geographically separated copy within the flat</td></tr>
<tr><td>Cloud archive</td><td>Cloud storage</td><td>Continuous</td><td>Off-site copy for worst-case scenarios (fire, theft)</td></tr>
</table>

<h2>Proxmox VM/LXC backups, three copies, two machines</h2>
<table>
<tr><th>Copy</th><th>Target</th><th>Frequency</th></tr>
<tr><td>1, original</td><td>Proxmox host itself</td><td>Daily</td></tr>
<tr><td>2, primary offsite</td><td>Synology NAS (different machine)</td><td>Daily, right after copy 1</td></tr>
<tr><td>3, secondary offsite</td><td>Raspberry Pi backup target, different room</td><td>Daily (skipped one day/week to avoid network contention with the weekly NAS sync)</td></tr>
</table>

<h2>Design principles</h2>
<ul>
<li>Backups always cross at least one machine boundary, nothing is considered "backed up" if it only lives on the source machine's local disk.</li>
<li>Weekly and daily jobs are scheduled to avoid saturating the internal power-line network link used by the offsite backup target.</li>
<li>All scheduled jobs ping a dead-man's-switch monitoring service; a missed backup triggers an alert.</li>
<li>Power to the offsite drive is only switched on for the duration of its weekly sync, to save power and extend disk life.</li>
</ul>

</div>