🛡️ FlexGuard

A modular, efficient, and version-aware backup tool for modern workflows.

---

📖 Why FlexGuard?

FlexGuard was created to address the limitations of traditional backup tools. Existing solutions often:

• Duplicate large amounts of unchanged data, wasting storage and time.
• Provide limited control over compression and file grouping.
• Lack clear versioning and the ability to restore older file states efficiently.
• Fail to handle ransomware resilience or WORM-like protection.
• Do not integrate well with modern multi-destination setups (NAS, cloud, USB).

FlexGuard aims to deliver:

• Efficient full and differential backups.
• Fine-grained file versioning and restore capabilities.
• Modern compression (Zstd, Brotli, GZip) with chunk-based storage.
• Minimal memory usage via streaming and temp files.
• Modular architecture that can grow with future requirements.

---

✨ Features

• Full & Differential Backups: Full backups monthly, differential backups daily.
• Chunk-Based Storage: Files grouped into compressed chunks (.fgchunk).
• Compression Options: GZip, Brotli, Zstd (Zstd recommended for best speed).
• SHA-256 Hashing: Data integrity checks for every file.
• Low Memory Usage: <100 MB memory footprint thanks to streaming.
• Interactive Restore Selector: Directory/Tree views, filtering, select-all, and clear-all.
• Logging & Performance Metrics: BackupRegistry and PerfLogger for detailed job statistics.
• Pluggable Architecture: Replaceable components for compression, logging, and grouping.

---

🏗️ Project Structure

FlexGuard is organized into multiple projects:

• FlexGuard.Core – Core backup and restore logic (chunking, compression, hashing, manifests).
• FlexGuard.CLI – Command-line interface, argument parsing, and interactive restore selector.
• FlexGuard.Benchmark – Performance and compression benchmark utilities.
• FlexGuard.UI (planned) – Windows Forms-based UI for job management and restores.
• FlexGuard.Tests (planned) – Unit and integration tests.

---

🚀 Quick Start

Requirements

• .NET 8 SDK or newer.
• Windows (Linux support planned in future versions).

Installation

Clone the repository and build with .NET:

git clone https://github.com/RudiHansen/FlexGuard.git
cd FlexGuard
dotnet build

Or download the pre-built binary from the Releases page (planned).

Example Usage

Perform a full backup:

flexguard --jobname "MyBackup" --mode full --compression zstd

Restore selected files:

flexguard --jobname "MyBackup" --mode restore

Show help:

flexguard --help

---

⚙️ Configuration

FlexGuard uses a JSON-based job configuration file (job_default.json) to define backup sources, destinations, and restore targets.
Copy job_default.json to create your own job file, e.g.:

cp job_default.json my_job.json

Fields:

• JobName: Unique name for the backup job (e.g., "PhotosBackup").
• Sources: A list of source folders to include in the backup.
  • Path: Absolute or relative path to the folder to back up.
  • Exclude: A list of patterns or folder names to skip (e.g., ["*.tmp", "bin", "obj"]).
• DestinationPath: The directory where backup chunks, manifests, and logs will be stored.
• RestoreTargetFolder: When performing a restore, this folder is where selected files will be restored.

Example:

{
  "JobName": "default",
  "Sources": [
    {
      "Path": "C:/Temp",
      "Exclude": [ "*.tmp", "bin", "obj" ]
    },
    {
      "Path": "D:/Projects",
      "Exclude": [ "bin", "obj" ]
    }
  ],
  "DestinationPath": "E:/Backups/FlexGuard",
  "RestoreTargetFolder": "C:/RestoredFiles"
}

---

⚙️ CLI Options

Argument	Description
--jobname <name>	Specifies the backup job name.
--mode <full|diff|restore>	Backup mode: Full, Differential, or Restore.
--maxfiles <number>	Max number of files per chunk group. (Default: 1000)
--maxbytes <size>	Max total size per chunk group. (Default: 1GB)
--compression <method>	Compression method: gzip, brotli, zstd. (Default Zstd)
--measure-compression	Planned feature for compression ratio logging.
-v or --version	Displays the current version.
-h or --help	Displays help information.

---

📦 Roadmap

• v0.4 (Planned):

  • Diff-based storage for file versioning.
  • Hash-per-chunk and optional manifest signing.
  • Transaction-safe manifest writes.
  • Expanded test coverage.

• Future:

  • SCP/SSH and cloud targets (OneDrive, S3).
  • UI layer (Windows Forms or alternative).
  • Retention and pruning policies.
  • WORM-like backup protection.

---

🧪 Development & Contribution

FlexGuard is currently in beta (v0.3). Contributions, bug reports, and suggestions are welcome.

1. Fork the repo.
2. Create a feature branch.
3. Submit a PR with detailed description and tests.

---

📜 License

This project is licensed under the MIT License – see LICENSE for details.

---

📞 Contact

Developed by Rudi Stensborg Hansen.
For issues and feedback, please open a GitHub Issue.