Learn Proxmox Backup Server - VM/CT Backup from Proxmox VE

#Introduction

Your PBS server is up from episode 3 — now we connect it to the real world: Proxmox VE. Episode 4 is the most satisfying moment of the series: your VMs and CTs start being protected by deduplicated, encrypted backups. It is also the first episode where two tools work together — PVE as the orchestrator, PBS as the storage engine.

Imagine PVE like an office that arranges all document deliveries, and PBS like a central archive warehouse. You simply give the office the warehouse address (server + datastore + fingerprint), and the office handles the schedule and delivery contents.

#Integrating PBS with Proxmox VE

#Adding PBS as Storage

In the PVE web UI: Datacenter → Storage → Add → Proxmox Backup Server. Fill in:

• ID: the storage name in PVE (e.g. pbs1).
• Server: PBS hostname/IP.
• Username: the PBS user created in episode 3 (e.g. backup@pam).
• Password: the user password, or paste a token from episode 12.
• Datastore: the datastore name in PBS (e.g. store1).
• Fingerprint: the PBS TLS certificate fingerprint (obtained from proxmox-backup-manager cert info on PBS, or from the web UI login page).

pvesm add pbs pbs1 \
  --server 10.0.1.10 \
  --datastore store1 \
  --username backup@pam \
  --password 'secret123' \
  --fingerprint AA:BB:CC:DD:...

pvesm add pbs registers a PBS-type storage. Verify with pvesm status:

pvesm status

Status active means PVE successfully connected to PBS. Keep the fingerprint somewhere safe — it serves to verify identity (anti man-in-the-middle) on every connection.

#Choosing the Backup Target

Once the storage is active, you can select it as the target in two places:

• Datacenter → Backup: backup jobs for many VMs/CTs at once.
• VM/CT → Backup: one-off manual backup per VM/CT.

The target storage is filled with the ID you created earlier (e.g. pbs1). PBS also offers extra options at the job level: compression (zstd default), mode, notification, and prune-backups (retention — episode 8).

#Performing VM/CT Backups

#Backup Modes: Guest Agent, Snapshot, Suspend, Stop

The mode determines how the VM disk is read during backup:

• Snapshot (default): the VM filesystem is snapshotted briefly (reliable via storage that supports snapshots such as ZFS/LVM). The VM does not stop, but write activity may be briefly interrupted.
• Suspend: the VM is suspended briefly for full consistency, then resumed. Safer for high-write workloads, but there is a short downtime.
• Stop: the VM is stopped, backed up, then started again. The most consistent, the most disruptive — only for special cases.
• Guest agent: if the qemu-guest-agent is installed in the VM, PBS uses fstrim and requests a filesystem freeze via the agent so the snapshot is consistent from inside the OS, and empty blocks can be thined. Enable it in PVE: VM → Options → QEMU Guest Agent → Enabled.

#Running a Manual Backup

From VM → Backup, or via the vzdump CLI:

vzdump 100 --storage pbs1 --mode snapshot --compress zstd

vzdump is the PVE backup engine; when the target is PBS, it calls proxmox-backup-client behind the scenes. For CTs, the command is the same — LXC is supported natively.

#Scheduling Regular Backups

Create a scheduled job in Datacenter → Backup → Add, set:

• Storage: pbs1.
• Schedule: PVE cron, e.g. daily at 02:30 (0 2 * * *) and weekly.
• Selection mode: all VMs/CTs, or per VM ID/tag/notes.
• Retention (prune-backups): start with keep-last 7, keep-daily 14 — details in episode 8.

This job will run automatically and report status in the PVE backup column.

#Verifying Snapshots in PBS

After the backup finishes, check from the PBS side that the snapshot really exists:

proxmox-backup-client snapshot list \
  --repository backup@pbs@10.0.1.10:store1

Or from the PBS web UI: navigate to Datastore → store1, and see the backup group per VM/CT with the latest snapshot timestamp. Status "OK" and the original vs dedup sizes will be shown here.

#Closing

Key takeaways:

• Add PBS via Datacenter → Storage → Add → Proxmox Backup Server or pvesm add pbs.
• You must fill in the correct server, username, password/token, datastore, and fingerprint.
• Backup modes: snapshot (default), suspend, stop — add a guest agent for better consistency.
• vzdump runs the backup; a PBS target calls proxmox-backup-client internally.
• Scheduling in Datacenter → Backup enables automatic regular backups.
• Verify snapshots appear in PBS via proxmox-backup-client snapshot list.

In the next episode, episode 5, we will restore — full VM restore to the same or a different PVE, plus file-level recovery by mounting a snapshot to grab individual files without a full restore. This is the capability you will rely on most when disaster actually strikes!