Proxmox Backup Server Setup: Installation, Datastores, and PVE Integration

What Is Proxmox Backup Server?

Proxmox Backup Server (PBS) is a dedicated backup solution designed specifically for Proxmox VE environments. It provides incremental, deduplicated backups of VMs and containers with optional client-side encryption. Unlike generic backup tools, PBS understands Proxmox's storage formats natively, offering fast backup and restore operations with minimal storage overhead thanks to content-addressable deduplication.

PBS can run on a separate physical server, inside a VM, or even on a Proxmox VE host itself (though a dedicated machine is recommended for production).

Installing Proxmox Backup Server

Download the PBS ISO from the official Proxmox website and install it on a dedicated machine or VM. The installer is straightforward, similar to the Proxmox VE installer. After installation, access the web UI at https://YOUR_PBS_IP:8007.

Alternatively, install PBS on an existing Debian 12 (Bookworm) system:

# Add the PBS repository
echo "deb http://download.proxmox.com/debian/pbs bookworm pbs-no-subscription" > /etc/apt/sources.list.d/pbs.list

# Add the Proxmox repository key
wget https://enterprise.proxmox.com/debian/proxmox-release-bookworm.gpg -O /etc/apt/trusted.gpg.d/proxmox-release-bookworm.gpg

# Install PBS
apt update
apt install proxmox-backup-server -y

Creating a Datastore

A datastore is a directory on the PBS server where backup data is stored. Ideally, use a dedicated disk or partition separate from the OS.

Prepare the storage:

# Create a filesystem on a dedicated disk
mkfs.ext4 /dev/sdb1
mkdir -p /mnt/backup-storage
echo "/dev/sdb1  /mnt/backup-storage  ext4  defaults  0 2" >> /etc/fstab
mount -a

Create the datastore via the web UI under Administration > Storage / Disks > Directory, or via CLI:

proxmox-backup-manager datastore create main-backups /mnt/backup-storage

The datastore is immediately available. PBS automatically creates the internal chunk store structure for deduplication.

Connecting PBS to Proxmox VE

To add your PBS server as a storage target in Proxmox VE, you need the PBS server's API fingerprint.

Get the fingerprint on the PBS server:

proxmox-backup-manager cert info | grep Fingerprint

This returns a SHA-256 fingerprint like:

Fingerprint (sha256): ab:cd:ef:12:34:56:78:90:ab:cd:ef:12:34:56:78:90:ab:cd:ef:12:34:56:78:90:ab:cd:ef:12:34:56:78:90

On your Proxmox VE node, go to Datacenter > Storage > Add > Proxmox Backup Server:

• ID: pbs-main
• Server: PBS server IP or hostname
• Username: root@pam (or a dedicated backup user)
• Password: the PBS user's password
• Datastore: main-backups
• Fingerprint: paste the fingerprint from above

Or via command line on the PVE node:

pvesm add pbs pbs-main \
    --server 192.168.1.60 \
    --username root@pam \
    --password YOUR_PASSWORD \
    --datastore main-backups \
    --fingerprint "ab:cd:ef:12:..." \
    --content backup

Creating Backup Jobs

With PBS connected, you can create scheduled backup jobs in Proxmox VE. Go to Datacenter > Backup > Add:

• Storage: pbs-main
• Schedule: e.g., daily at 02:00
• Selection mode: All, or specific VMs/containers
• Mode: Snapshot (recommended; does not stop the VM)
• Notification: configure email alerts for failures

Or schedule via CLI:

pvesh create /cluster/backup \
    --storage pbs-main \
    --schedule "02:00" \
    --all 1 \
    --mode snapshot \
    --mailnotification failure \
    --mailto admin@example.com

Deduplication

PBS deduplicates data automatically at the chunk level. When backing up multiple similar VMs (e.g., from the same template), only unique chunks are stored. Subsequent incremental backups of the same VM only transfer changed chunks.

Check deduplication efficiency on the PBS server:

proxmox-backup-manager datastore list

The output shows total data size versus actual disk usage. Deduplication ratios of 3:1 to 10:1 are common in environments with similar VMs.

Client-Side Encryption

PBS supports client-side encryption, meaning data is encrypted before it leaves the Proxmox VE host. The PBS server never sees unencrypted data. This is essential for offsite backup scenarios.

Generate an encryption key on the PVE node:

proxmox-backup-client key create --kdf scrypt /etc/pve/priv/pbs-encryption-key.json

Add the key to your PBS storage configuration:

pvesm set pbs-main --encryption-key /etc/pve/priv/pbs-encryption-key.json

Back up the encryption key file securely. Without it, encrypted backups are permanently unrecoverable. Store copies in multiple secure locations, such as a password manager or offline storage.

Prune and Garbage Collection

Prune schedules control how many backup snapshots are retained. Configure prune settings on the datastore via the PBS web UI, or via CLI:

proxmox-backup-manager datastore update main-backups \
    --keep-daily 7 \
    --keep-weekly 4 \
    --keep-monthly 6

This keeps 7 daily, 4 weekly, and 6 monthly backups per VM. Older backups are marked for removal.

After pruning, run garbage collection to actually free disk space by removing orphaned chunks:

proxmox-backup-manager garbage-collection start main-backups

Schedule automatic garbage collection in the PBS web UI under the datastore's Options tab. Running it weekly is typically sufficient.

Verification

PBS can verify backup integrity by reading all chunks and checking their checksums:

proxmox-backup-manager verify main-backups

Schedule regular verification jobs to catch silent data corruption early. A verified backup is one you can trust to restore.

Proxmox Backup Server is a critical part of any production Proxmox deployment. Paired with ProxmoxR for day-to-day VM management, you get both operational visibility and data protection across your entire infrastructure.