Bash Script for Local to NAS File Backup

This project provides a Bash script designed for automating the backup of files from a local system to a Network-Attached Storage (NAS) unit. It's built with simplicity, efficiency, and robust error handling in mind.

How It Works

• Automated Backup: Utilizes a Bash script to streamline the file backup process from local systems to NAS devices.
• Efficient Synchronization: Employs rsync for intelligent file transfer, ensuring only differences are sent to minimize network load and speed up backups.
• Permission Control: Offers explicit control over the permissions and ownership of the transferred files, ensuring they remain accessible and manageable on the NAS.

Process Overview

1. Initialization: On execution, reads source and destination paths from the paths.conf configuration file.
2. Robust Error Handling: Implements stringent error checks, terminating and logging on any failures to facilitate troubleshooting.
3. Synchronization: Executes rsync for each source-destination pair, offering real-time progress feedback and summarizing transfer statistics upon completion.
4. Completion: Calculates and displays the total time taken for the backup process.

Configuration

Prerequisites

• Bash shell environment.
• rsync installed on both the local and NAS systems.
• Network connectivity with the NAS.
• Appropriate permissions for accessing source locations and writing to destinations.

Setup

Setting Up paths.conf

To configure the script for your environment, you need to create a paths.conf file. ( It should be located in the same directory as your backup script)

rename 'paths_template.conf' to 'paths.conf'

declare -a SRC=(
    "/path/to/local/directory1/"
    "/path/to/local/directory2/"
    ...
)

declare -a DST=(
    "user@nas-ip:/path/to/nas/directory1/"
    "user@nas-ip:/path/to/nas/directory2/"
    ...
)

This file specifies the source directories on your local system and the corresponding destination paths on your NAS where the backups will be stored.

Customize the Paths

• Replace /path/to/local/directory1/, /path/to/local/directory2/, etc., with the actual paths of the directories on your local system you wish to back up.
• Replace user@nas-ip:/path/to/nas/directory1/, user@nas-ip:/path/to/nas/directory2/, etc., with the appropriate SSH-accessible paths on your NAS where each local directory should be backed up.

Script Options

The backup script includes configurable options for rsync to fine-tune the synchronization process. These can be adjusted in the script file directly:

• OPTS="-auvO --chmod=Du=rwx,Dg=rwx,Do=rx,Fu=rw,Fg=rw,Fo=r --stats": This option string includes:
  • -a: Archive mode to copy files recursively and preserve symbolic links, file permissions, user & group ownerships (except when overridden by --chmod), and timestamps.
  • -u: Skip files that are newer on the receiver.
  • -v: Verbose mode to provide detailed output.
  • -O: Omit directories from being included in the modification time comparisons, useful for avoiding unnecessary directory updates.
  • --chmod: Explicitly set file and directory permissions on the destination.
  • --stats: Give a summary at the end of the transfer for a quick overview of what was transferred.

Feel free to modify the OPTS string to match your specific backup requirements or preferences.

Running the script

You can run the script with the following command:

./file_syncer.sh

Please ensure that the script has execute permissions. If not, you can add execute permissions with the following command:

chmod +x script.sh

Create an alias to run the script

Open your .bashrc file in a text editor.

vim ~/.bashrc

Go to the end of the file and add the following line:

alias backup='/PATH/TO/YOUR/file_syncer.sh'

Save the file and exit the editor.

In order for your current terminal to recognize the new alias, you need to source your .bashrc file with the following command:

source ~/.bashrc

Now you can start your backup by simply typing

backup

Error Handling

The script ensures robust and user-friendly error handling:

• Immediate Exit on Error: Utilizes set -e to halt execution at the first sign of trouble, preventing cascading failures.

• Custom Error Reporting: Implements a handle_error() function, invoked with trap on any error, to report the precise line where an issue occurs, facilitating quicker diagnostics.

• Operation Feedback: Outputs detailed information post-backup, including the number of files transferred, for user verification and troubleshooting.

• Temporary File Management: Generates and subsequently cleans up temporary files for each backup operation, ensuring a tidy environment and aiding in error analysis if needed.

This streamlined error handling framework enhances the script's reliability, making it easier to use and maintain.