Configurer les sauvegardes Proxmox

Why this matters

A Proxmox host often runs your most important workloads — a NAS VM, your Docker host, maybe Home Assistant. If a disk dies or you break a VM during an upgrade, backups are what turn a disaster into a 10-minute restore. Proxmox has excellent built-in backups; you just need to configure them properly.

Two backup approaches

• vzdump — the built-in tool that creates full backups of a VM or container to a storage location (local directory, NFS, or PBS). Simple and reliable.
• Proxmox Backup Server (PBS) — a dedicated companion that adds incremental, deduplicated, verified backups. It's dramatically more space- and time-efficient once you have several VMs. Highly recommended if you can run it.

Step 1: Add a backup storage target

In the Proxmox web UI, go to Datacenter → Storage → Add. Good options:

• NFS/CIFS share on your NAS — keeps backups off the Proxmox host's disks.
• Directory on a separate physical disk.
• Proxmox Backup Server — if you've set up PBS (see below).

Never store backups only on the same disk as the VMs — a disk failure would take both.

Step 2: Create a scheduled backup job

Go to Datacenter → Backup → Add:

1. Storage: your backup target.
2. Schedule: e.g. daily at 02:00.
3. Selection mode: all VMs, or pick specific ones.
4. Mode:
   • Snapshot — minimal downtime (recommended for most).
   • Suspend / Stop — for workloads that need a consistent, quiesced state.
5. Compression: ZSTD is fast and effective.
6. Retention: set how many to keep (see next step).

Step 3: Set sensible retention

Under the job's Retention (or Prune) settings, a good home policy is:

keep-daily=7
keep-weekly=4
keep-monthly=6

This keeps a week of dailies, a month of weeklies, and half a year of monthlies — enough to recover from mistakes you notice late, without unlimited growth. PBS deduplication makes this cheap.

Step 4: Set up Proxmox Backup Server (recommended)

If you can dedicate a machine or VM to PBS:

1. Install PBS from its ISO (or as a VM on separate storage).
2. Create a datastore on a dedicated disk.
3. In Proxmox, add the PBS as storage using its fingerprint and an API token.
4. Point your backup job at the PBS datastore.

You now get incremental backups (only changed blocks are sent), automatic deduplication across all VMs, and built-in verification that periodically checks backups are actually restorable.

Step 5: Verify and test restores

Backups you've never restored are just hope. Do both:

• Verification: enable scheduled verify jobs in PBS so corruption is caught early.
• Test restore: at least quarterly, restore a VM to a new VM ID in an isolated state and boot it. Confirm it actually works.

# Restore is available in the UI, or via CLI, e.g.:
qmrestore /path/to/backup.vma.zst 999

Step 6: Get a copy offsite

Local backups protect against disk failure and mistakes, not fire or theft. Complete the 3-2-1 strategy by syncing PBS to a remote PBS or pushing encrypted archives to cloud storage.

Troubleshooting

• Snapshot mode fails — the guest may lack the QEMU guest agent; install it or use suspend mode.
• Backups fill the disk — tighten retention and confirm pruning runs.
• Slow backups — use ZSTD, and prefer PBS incrementals over full vzdump to NFS.

Next steps

Add a monitor that alerts you if a backup job fails (Proxmox can email on failure, or ping an Uptime Kuma push monitor on success) so a silent failure never goes unnoticed.