Synology GitHub Backup

A simple, safe, and fully self-contained GitHub backup solution for Synology NAS.

This solution mirrors all repositories from your personal GitHub account to a shared folder on your Synology. It performs read-only operations and never writes back to GitHub.

It is designed to run as a Scheduled Task in DSM without external dependencies beyond Git and standard system tools.

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What This Script Does

• Fetches all repositories from your personal GitHub account
• Mirrors each repository using git clone --mirror
• Updates repositories on subsequent runs using git fetch --all --prune
• Stores repositories in a dedicated Synology shared folder
• Optionally creates readable working copies of your repositories
• Writes a detailed log file
• Tracks the last successful run

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What Is Backed Up

• Full Git history
• All branches
• All tags
• All refs

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What Is Not Backed Up

• Issues
• Pull requests
• GitHub Actions logs
• Repository settings

This is a Git-level backup, not a full GitHub platform export.

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Requirements

1. Install Git Server

Open DSM → Package Center → Install Git Server

Git Server installs the required Git binary. You do not need to configure it as a Git hosting server.

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2. Enable SSH (One Time Only)

Go to:

Control Panel → Terminal & SNMP → Enable SSH

SSH is required once to verify that Git is installed correctly (git --version).

After setup is complete, SSH can be disabled again.

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3. Create a Dedicated Shared Folder

Create a new shared folder, for example:

Github Backups

Keeping backups in a dedicated share makes protection and versioning easier.

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Creating a GitHub Token

Create a Classic Personal Access Token:

GitHub → Settings → Developer Settings → Personal Access Tokens → Tokens (Classic)

Required scope:

repo

No additional scopes are required.

If your repositories are inside an organization, ensure the token is approved for that organization.

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Installing the Script

Open:

DSM → Control Panel → Task Scheduler

Create:

Create → Scheduled Task → User-defined script

Run the task as a user that has write access to the shared folder.

Paste the full backup script into the Run command field.

Configure:

• TOKEN → Your GitHub Personal Access Token
• BACKUP_SHARE → Your Synology shared folder path
• WORKING_MODE → Optional working copy behavior

Example:

/volume1/Github Backups

Make sure the path matches exactly what File Station shows.

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Working Copy Modes (Optional)

The script supports three modes:

WORKING_MODE="none" (Default)

Mirror backup only.

• Stores only .git mirror repositories
• Most storage efficient
• Recommended for pure backup scenarios

Use this if:

• You only care about disaster recovery
• You want the smallest storage footprint
• You are comfortable using Git to restore

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WORKING_MODE="default"

Creates one readable working copy per repository on the default branch (usually main).

Structure:

Github Backups/ repos/ working/ owner/ repo/ (actual source files)

Use this if:

• You want easy file browsing in File Station
• You only need the default branch
• You want minimal duplication

Recommended for most users who want convenience without large storage growth.

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WORKING_MODE="all"

Creates a subdirectory per branch using Git worktrees.

Structure:

Github Backups/ working/ owner/ repo/ _repo/ branches/ main/ dev/ feature-x/

Use this if:

• You need file-level access to every branch
• You want full branch visibility without Git commands
• Storage usage is not a concern

Warning:

This mode consumes more disk space on repositories with many branches.

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Excluding repositories (optional)

If you want to skip specific repositories entirely, add an exclude list to the script.

Add this in the CONFIG section:

Space separated list of repos to exclude completely (owner/repo)

EXCLUDE_REPOS="ORG/BigRepoA"

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Scheduling

Set the schedule to run daily during low activity hours.

Optionally enable email notifications for failures.

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Logging

The script creates:

Github Backups/logs/github-backup.log
Github Backups/logs/last-run.txt

These show:

• What was cloned
• What was updated
• When the last run completed
• Whether any errors occurred

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Versioning and Protection

The script maintains a current mirror of each repository. It does not create historical versions of the backup set.

For proper protection, use Synology’s built-in features.

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Snapshot Replication (Recommended)

If your volume uses Btrfs:

Enable scheduled snapshots for the shared folder.

Benefits:

• Point-in-time recovery
• Fast restore
• Protection against accidental deletion
• Protection against ransomware

Recommended baseline:

• Daily snapshots
• 30-day retention

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Hyper Backup

Use Hyper Backup to protect the shared folder to:

• Another NAS
• External USB disk
• Synology C2
• Other supported cloud providers

Recommended strategy:

Mirror → Snapshots → Hyper Backup

This gives you:

• Local restore capability
• Version history
• Off-device protection

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Verifying Your Backup Locally

To confirm the .git mirror contains everything:

Step 1: Copy a Mirror Repository

From File Station, copy:

\NAS-NAME\Github Backups\repos\owner\repo.git

to your local machine, for example:

C:\Temp\repo.git

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Step 2: Inspect the Mirror

Open PowerShell or Git Bash:

git --git-dir "C:\Temp\repo.git" show-ref --heads

List tags:

git --git-dir "C:\Temp\repo.git" tag

View history:

git --git-dir "C:\Temp\repo.git" log --oneline --all

If branches and commits appear correctly, your backup is complete.

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Step 3: Create a Working Copy (Optional)

cd C:\Temp
git clone "C:\Temp\repo.git" repo
cd repo
git branch -a

Switch branches:

git checkout dev

If files appear correctly, your backup is fully restorable.

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Cleanup

After testing, you can safely delete the copied .git folder and the test working directory from your local machine. This does not affect the backup stored on your Synology.