Installing Proxmox Backup Server (PBS) on Ubuntu 22.04 Laptop

Part of the Proxmox Baremetal Journey series

I broke my install more times than I'd like to admit, but by the end I learned a ton about how PBS works under the hood. This post documents everything I learned while setting up Proxmox Backup Server to help others avoid my mistakes and establish production-level workflows.

Think of this as both a how-to guide and a "don't make my mistakes" story.

🔧 What Went Wrong (And How I Fixed It)

PBS is very strict about ownership and permissions. If they're wrong, nothing works. Here are the main traps I fell into:

Permission Issue #1 → The proxmox-backup directory was owned by root:root. PBS needs it owned by backup:backup.

Permission Issue #2 → I used 755 for the config directory. PBS requires 700.

Permission Issue #3 → My datastore subdirectories weren't owned by backup:backup. That blocked PBS from creating the crucial .chunks directory.

🛠 Clean Installation Guide

1. Update & Prepare System

sudo apt update && sudo apt upgrade -y
sudo apt install curl wget gnupg lsb-release apt-transport-https -y

2. Add the Proxmox Repository

echo "deb http://download.proxmox.com/debian/pbs bookworm pbs-no-subscription" | sudo tee /etc/apt/sources.list.d/pbs.list
wget -qO- http://download.proxmox.com/debian/proxmox-release-bookworm.gpg | sudo gpg --dearmor -o /etc/apt/trusted.gpg.d/proxmox-release-bookworm.gpg

3. Fix GPG Key Issues (if needed)

sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys 1140AF8F639E0C39
sudo apt update

4. Remove Old Packages (for a fresh reinstall)

sudo apt-get purge proxmox-backup proxmox-backup-client proxmox-backup-docs proxmox-backup-server -y
sudo apt-get purge proxmox-kernel-* proxmox-default-kernel -y
sudo rm -rf /etc/proxmox-backup /etc/systemd/system/proxmox-backup*
sudo rm -rf /mnt/pbs_backup/*

5. Install PBS

sudo apt install proxmox-backup-server -y

6. Create Datastore Directory

sudo mkdir -p /mnt/pbs_backup/datastore1

7. Fix Permissions

# Datastore ownership
sudo chown -R backup:backup /mnt/pbs_backup/datastore1

# Create and secure PBS config directory 
sudo mkdir -p /etc/proxmox-backup
sudo chown -R backup:backup /etc/proxmox-backup
sudo chmod 700 /etc/proxmox-backup

# Manually create .chunks directory (if PBS doesn't create it automatically)
sudo -u backup mkdir -p /mnt/pbs_backup/datastore1/.chunks

8. Start PBS Services

sudo systemctl start proxmox-backup
sudo systemctl enable proxmox-backup
sudo systemctl start proxmox-backup-proxy
sudo systemctl enable proxmox-backup-proxy

📘 Key Takeaways

Permissions are critical:

• /etc/proxmox-backup → must be backup:backup with 700
• Datastores → must be backup:backup so PBS can create .chunks

Two services must run:

• proxmox-backup → API server
• proxmox-backup-proxy → Web interface

Troubleshooting Tips

If you encounter issues, check these common points:

1. Verify service status: sudo systemctl status proxmox-backup proxmox-backup-proxy

2. Check permissions: ls -la /etc/proxmox-backup and ls -la /mnt/pbs_backup/datastore1

3. Review logs: sudo journalctl -u proxmox-backup -f

Remember: when in doubt, proper permissions are usually the answer with PBS.