Proxmox Backup Server Setup: Complete PBS Guide for Businesses

If you run Proxmox VE as your virtualization platform, you need a reliable backup strategy. Proxmox Backup Server (PBS) is the native backup solution within the Proxmox ecosystem, purpose-built for backing up virtual machines and containers. With deduplication, client-side encryption, and block-level incremental backups, PBS provides everything businesses need for professional data protection — without license fees.

Why Proxmox Backup Server?

Compared to the dump-based backups built into Proxmox VE, PBS offers significant advantages:

Feature	VE Dump Backup	Proxmox Backup Server
Backup type	Full (every time)	Block-level incremental
Deduplication	No	Yes (chunk-based)
Storage requirements	High	50–80% less
Backup duration	Minutes to hours	Seconds to minutes
Encryption	No	Client-side (AES-256-GCM)
Verify jobs	Manual	Automated

PBS splits each backup into small data blocks (chunks), calculates their checksums, and stores identical blocks only once. The result: even with daily backups of dozens of VMs, storage consumption remains manageable.

Installation: Dedicated Server or VM?

PBS can be installed on a dedicated physical server or as a VM within Proxmox VE. For production environments, we recommend a dedicated server, as it operates independently from the hypervisor — if the Proxmox VE host fails, backups remain accessible.

Installation uses the official ISO image:

# Download ISO and write to USB drive
dd if=proxmox-backup-server_3.x.iso of=/dev/sdX bs=4M status=progress

After booting, the installer walks you through configuration: network, timezone, root password, and — critically — the filesystem selection for the system disk.

Setting Up a Datastore

The datastore is the central storage location for all backups. PBS supports local directories, with ZFS as the filesystem strongly recommended. ZFS provides block-level checksums, compression, and self-healing in redundant configurations.

# Create ZFS pool (mirror of two disks)
zpool create -o ashift=12 backuppool mirror /dev/sdb /dev/sdc

# Enable compression
zfs set compression=zstd backuppool

# Create directory for the datastore
zfs create backuppool/datastore1

Then create the datastore through the PBS web interface: Datastore > Add and select the /backuppool/datastore1 directory. The datastore is immediately ready for use.

Connecting PBS to Proxmox VE

The connection is configured in the Proxmox VE web interface under Datacenter > Storage > Add > Proxmox Backup Server:

1. Server: IP address or hostname of the PBS
2. Username: backup@pbs (create a dedicated backup user)
3. Password: Password of the PBS user
4. Datastore: Name of the configured datastore
5. Fingerprint: SHA-256 fingerprint of the PBS certificate (displayed on first connection)

You can retrieve the fingerprint on the PBS server:

proxmox-backup-manager cert info | grep Fingerprint

After saving, the PBS datastore appears as a storage target in Proxmox VE and can be used for backup jobs.

Configuring Backup Jobs

Backup jobs are created in Proxmox VE under Datacenter > Backup > Add:

• Storage: Select the PBS datastore
• Schedule: Define the timing (e.g., 01:00 for daily backups at 1 AM)
• Selection mode: All VMs, specific VMs, or VMs with certain tags
• Mode: Snapshot (recommended — no downtime)
• Notification: Email alerts on success or failure

You can create separate backup jobs with different schedules for different VM groups. Critical production VMs can be backed up hourly, while development systems receive a daily backup.

Example Schedule for an SMB

VM Group	Schedule	Retention
Production VMs (ERP, email)	Every 4 hours	14 daily, 8 weekly, 12 monthly
Database servers	Hourly	24 hourly, 7 daily, 4 weekly
Development / test	Daily at 02:00	7 daily, 4 weekly

Client-Side Encryption

PBS supports AES-256-GCM encryption directly on the client (the Proxmox VE host). Data is encrypted before transmission — the PBS server never sees unencrypted content. This is particularly important for offsite backups or when the backup server is operated by a third party.

Encryption is enabled when adding the PBS storage in Proxmox VE:

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

Enter the generated key in the storage dialog under Encryption Key. Critical: Store the key in a secure, separate location — without it, backups cannot be restored.

Retention, Pruning, and Garbage Collection

Retention policies define how long backups are kept. PBS offers granular settings per datastore:

• keep-last: Number of most recent backups
• keep-daily: Daily backups (one per day)
• keep-weekly: Weekly backups
• keep-monthly: Monthly backups
• keep-yearly: Yearly backups

Pruning marks backups that are no longer needed according to the retention policy. Garbage Collection (GC) then removes unreferenced chunks and actually frees the storage space. Schedule GC regularly — ideally daily after pruning.

# Set retention settings via CLI
proxmox-backup-manager datastore update datastore1 \
  --keep-daily 14 --keep-weekly 8 --keep-monthly 12 --keep-yearly 2

# Start garbage collection manually
proxmox-backup-manager garbage-collection start datastore1

Setting Up Verify Jobs

Backups are only as valuable as their restorability. PBS offers automated verify jobs that check the integrity of all stored chunks. For encrypted backups, the cryptographic signature is verified without needing to decrypt the data.

Set up a verify job under Datastore > Verify Jobs > Add. A practical schedule: weekly on weekends when system load is low. Corrupted chunks are reported in the PBS dashboard and via email notifications.

Monitoring with DATAZONE Control

For businesses running multiple PBS instances or managing extensive backup landscapes, the built-in dashboard is often not sufficient. DATAZONE Control monitors your entire backup infrastructure centrally: backup status, datastore utilization, failed jobs, and verify results feed into a unified dashboard. Automatic alerts ensure that no failed backup goes unnoticed — even across dozens of VMs spanning multiple sites.

Frequently Asked Questions

How much storage does PBS need?

Thanks to chunk-based deduplication, PBS typically requires 30–50% of the storage that full backups would consume. For 10 VMs with a combined 2 TB of data and 14 daily backups, 1–2 TB of datastore capacity is often sufficient.

Can PBS back up physical servers?

Yes. The proxmox-backup-client can back up any directories and files from Linux systems to PBS — independent of Proxmox VE.

Is PBS suitable for GDPR-compliant backups?

Yes. Client-side AES-256 encryption ensures that backup data on the server is not readable. Combined with access controls and audit logging, PBS meets GDPR requirements for technical and organizational measures.

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Want to set up Proxmox Backup Server for your business? Contact us — we plan and implement your Proxmox infrastructure including a professional backup solution.