Robo-Backup

A simple Windows batch script for backing up folders to a network share (NAS) using robocopy. No dependencies, no credential storage -- just a single .bat file and an optional config.

Features

• Robocopy-powered -- incremental, accumulating backups that skip older files (/XO)
• Configurable -- set source, destination, username, and log directory in a backup.cfg file
• CLI overrides -- pass up to 4 positional arguments to override config values
• Simulate mode -- use /L to preview what would be copied without making any changes
• Secure -- password is always prompted interactively and never written to disk or Credential Manager
• Auto-cleanup -- network connections are always torn down after the run, regardless of success or failure
• Verbose logging -- every run produces a timestamped log with full robocopy output (console + file)
• Pure batch -- no PowerShell, VBScript, or external dependencies

Quick Start

1. Place simple-backup.bat in a folder of your choice.

2. Create a backup.cfg file in the same folder:

   SOURCE=C:\Users\John\Documents\Important
   DESTINATION=\\192.168.1.50\backup\john_docs
   USERNAME=nas_user
   LOG_DIR=C:\Users\John\BackupLogs

3. Run the script:

   simple-backup.bat

4. Enter your NAS password when prompted.

That's it. The backup runs, logs are written, and the network connection is cleaned up automatically.

Usage

Config File Only

simple-backup.bat

Reads all settings from backup.cfg and prompts only for the password.

Override via Command Line

simple-backup.bat [source] [destination] [username] [log_dir]

Example:

simple-backup.bat D:\Photos \\NAS\PhotosBackup nasadmin C:\TempLogs

Positional arguments override backup.cfg values. Any values not provided via CLI fall back to the config file, then to interactive prompts.

Simulate Mode

simple-backup.bat /L

Or with arguments:

simple-backup.bat /L D:\Photos \\NAS\PhotosBackup nasadmin

Runs everything normally but passes /L to robocopy, so it only lists files that would be copied without actually copying anything.

No Config, No Arguments

simple-backup.bat

Prompts interactively for source, destination, username, and password. Logs to the current directory.

Configuration

Create a file named backup.cfg in the same directory as the script.

Key	Description	Required
SOURCE	Path to the source folder to back up	Yes (unless provided via CLI)
DESTINATION	UNC network path to the backup destination (e.g., \\NAS\Backups\MyFolder)	Yes (unless provided via CLI)
USERNAME	NAS username for authentication	No
LOG_DIR	Directory where log files are written. Defaults to current directory if omitted	No

Rules:

• Lines starting with ;, #, or // are treated as comments
• Blank lines are ignored
• Values may contain spaces and = characters
• The script works fine if backup.cfg is missing -- it will fall back to CLI args or prompts

Value Resolution Priority

1. Command-line argument (highest)
2. backup.cfg value
3. Interactive prompt (lowest)

The PASSWORD is never read from a file or CLI argument. It is always prompted interactively.

Robocopy Flags

The script uses the following robocopy options:

Flag	Purpose
/E	Copy subdirectories, including empty ones
/R:5	Retry failed copies 5 times
/W:10	Wait 10 seconds between retries
/XO	Exclude older files (skip if destination is newer)
/NP	No progress percentage (cleaner output)
/TEE	Output to both console and log file
/V	Verbose file listing (includes skipped files)
/LOG+	Append output to log file

Not used: /MIR, /PURGE, /MOV, /MOVE -- this script never deletes or moves source files.

Logging

Each run produces a log file named backup_YYYYMMDD_HHMMSS.log in the configured LOG_DIR. The log contains the complete robocopy output, including:

• Source and destination paths
• Files copied and skipped (with reasons)
• Retry attempts
• Final summary table

The same output is displayed in the console in real-time.

Exit Codes

Code	Meaning
0	Success (no errors; robocopy exit code < 8)
1	Backup completed with errors (robocopy exit code >= 8)
Other	net use authentication failure (passes through the Windows error code)

Note: robocopy uses a bitmask for exit codes. Codes 0-7 indicate various levels of success (no changes, files copied, extra files detected, etc.). Codes >= 8 indicate actual errors.

Requirements

• Windows (any version with robocopy and net use)
• Access to a network share (SMB/CIFS)
• No third-party software

License

MIT