Automated Container Backup Exclusions for Proxmox

Problem Context

Users running Proxmox VE (PVE) with Docker/LXC containers struggle to exclude ephemeral data (like containerd snapshots) from backups. Manual exclusions fail because PVE lacks per-container controls, leading to bloated backups, storage costs, and risk of corrupted backups if exclusions are misconfigured.

Pain Points

Users waste hours manually mounting containers (pct mount) to fix permissions, then discover they’ve been backing up unnecessary containerd snapshots. Global exclusions don’t work for mixed stateless/stateful containers, and ChatGPT’s advice (e.g., ‘exclude containerd’) is risky without verification. Failed workarounds include reinstalls and hiring consultants.

Impact

Bloated backups increase cloud storage costs (e.g., Backblaze B2), and corrupted backups cause downtime. Users avoid switching to ‘Suspend’ backups (faster but riskier) because they can’t trust exclusions. The problem escalates with more containers, making it a recurring headache for DevOps teams.

Urgency

This is urgent because backups are mission-critical, and manual fixes are error-prone. Users can’t ignore it—either they waste time troubleshooting or risk data loss. The financial hit (storage costs + downtime) grows with cluster size, making it a ticking time bomb for unmanaged environments.

Target Audience

DevOps/SRE engineers and sysadmins managing Proxmox VE clusters with Docker/LXC containers. This includes small businesses, cloud providers, and enterprises using PVE for virtualization. Users who push backups to cloud storage (e.g., Backblaze B2, AWS S3. or rely on PVE’s built-in backups are most affected.

Solution Approach

A lightweight CLI + API tool that auto-detects Docker/LXC containers in Proxmox and lets users mark specific containers as ‘ephemeral’ (e.g., containerd snapshots, unused images). The tool integrates with PVE’s backup system to exclude these containers automatically, reducing backup size by 30–70% and eliminating manual fixes.

Key Features

1. Per-Container Exclusions: Lets users toggle exclusions for individual containers (e.g., ‘exclude containerd but keep Nginx’).
2. Backup Dry-Run: Simulates backups to verify exclusions work before running real backups.
3. Cloud Sync: Pushes exclusion rules to Backblaze B2/AWS S3 to ensure consistency across backups.

User Experience

Users install the CLI, run a one-time scan, and mark containers as ephemeral via a simple interface. The tool then handles exclusions automatically during backups. Users see smaller backups, faster ‘Suspend’ backups, and no more permission errors—all without manual intervention. Alerts notify them if exclusions fail.

Differentiation

Unlike manual pct mount fixes or global exclusions, this tool is *container-aware- and automated. It’s lighter than full backup managers (e.g., Veeam) and fills the gap PVE’s native tools ignore. The dry-run feature prevents corrupted backups, and cloud sync ensures exclusions persist across restores.

Scalability

Starts with Docker/LXC exclusions, then adds support for Kubernetes (via containerd) and custom scripts for other ephemeral data (e.g., logs). Pricing scales with cluster size (e.g., $50/mo for <50 containers, $100/mo for >50). API access allows integration with monitoring tools (e.g., Prometheus).

Expected Impact

Users save 30–70% on backup storage costs and reduce downtime from corrupted backups. They can safely use ‘Suspend’ backups (faster but riskier) and spend less time troubleshooting. The tool pays for itself in <1 month for most users, making it a no-brainer for DevOps teams.