Backing Up Desktop Files with Proton Drive CLI and Cron

Why Not the Desktop App?

Proton Drive offers a desktop sync application that keeps files in real-time sync between your machine and the cloud. It works well for many people, but I prefer the CLI approach for one reason: control.

With the CLI, I decide exactly what gets backed up, when, and how. Combined with cron jobs, this gives me predictable, auditable backups without background processes eating resources or silently overwriting things I didn’t intend.

Installation

Official Documentation: https://proton.me/support/drive-cli

The Proton Drive CLI is a single binary. On Fedora Linux (x86_64):

curl -L -o /tmp/proton-drive https://proton.me/download/drive/cli/0.9.0/linux-x64/proton-drive
chmod +x /tmp/proton-drive
sudo mv /tmp/proton-drive /usr/local/bin/proton-drive

Verify the checksum before running:

sha512sum /usr/local/bin/proton-drive
# Expected: 3533025ba69ae112b64e3e01fbcc1ad0688136a4043f6cf6a72886967d85fdcd9ec235479c2e113171614be5225bfba93427509a05ca5aa6071d924fa7e91ca8

Authentication

proton-drive auth login

This opens a browser for you to authorize with your Proton account. Keep the terminal open until authentication completes.

Creating Your Backup Structure

# Create a dedicated backup folder
proton-drive filesystem create-folder /my-files BACKUP-PLACEHOLDER

I name the backup folder after my machine’s hostname so each device has its own distinct backup directory.

Uploading Files

The key flags for automated backups:

• -f skip, Skip files that already exist on Proton Drive (don’t overwrite)
• -d merge, Merge folder contents instead of replacing entire folders

# Upload your Documents folder
proton-drive filesystem upload -f skip -d merge /home/elyons/Documents /my-files/BACKUP-PLACEHOLDER

# Upload a blog or project directory
proton-drive filesystem upload -f skip -d merge /home/elyons/Blog /my-files/BACKUP-PLACEHOLDER

The CLI reports a transfer summary: Uploaded: X items (Y MiB). If nothing changed, it uploads zero files. This makes repeated runs cheap and fast.

Other Conflict Strategies

Automating with Cron

Set up daily cron jobs for hands-off backups:

# Documents backup at 1 AM
0 1 * * * proton-drive filesystem upload -f skip -d merge /home/elyons/Documents /my-files/BACKUP-PLACEHOLDER >> ~/.local/log/proton-backup.log 2>&1

# Blog/project backup at 2 AM
0 2 * * * proton-drive filesystem upload -f skip -d merge /home/elyons/Blog /my-files/BACKUP-PLACEHOLDER >> ~/.local/log/proton-backup.log 2>&1

Important: Always include -f and -d flags in cron jobs. Without them, the CLI prompts for conflict resolution interactively and will hang waiting for input.

Useful Commands

# List files with JSON output (great for scripting)
proton-drive filesystem list -j /my-files/BACKUP-PLACEHOLDER

# Check folder size
proton-drive filesystem size /my-files/BACKUP-PLACEHOLDER/Documents

# Full account export (takeout), read-only, never modifies your drive
proton-drive takeout run -i my-files,photos,revisions ~/backup-takeout/

# Share a folder with someone
proton-drive sharing invite -u [email protected] -r viewer /my-files/BACKUP-PLACEHOLDER/Documents

Why This Works for Me

• Predictable: Cron runs at known times, not random sync intervals
• Auditable: Log files show exactly what was uploaded each run
• No background processes: The CLI only runs when it needs to
• Delta uploads: Only changed files transfer, fast after the initial backup
• Privacy-first: Proton Drive is end-to-end encrypted, and I control the sync behavior

The desktop app is fine if you want set-and-forget. But for people who like knowing exactly what’s happening with their data, the CLI + cron combination gives you that visibility without sacrificing convenience.