A simple backup helper script for Synology NAS that copies a Hyper Backup file or folder from a fixed source path to an external USB-mounted destination, then sends an email notification about the result.

copy2usb.sh

What it does

• Verifies the source backup path exists before attempting to copy.
• Verifies the destination USB mount path exists and is reachable.
• Copies the source to the destination using cp -rf.
• Checks whether the destination copy exists after a successful cp.
• Sends an email notification for success, warning, or failure.

Script functions

send_mail()

This helper function builds a simple email message with headers and body text, then pipes it into /bin/ssmtp.

• From: configured by MAIL_FROM
• To: configured by MAIL_TO
• Subject: set according to success or failure state
• Date: uses the current date in RFC 2822 format

Configuration

Edit the top of copy2usb.sh to match your environment:

• SRC – source file or directory to copy
• DST – destination directory mounted from the USB drive
• SMTP – SMTP server address used by ssmtp (in this script the variable is defined but not directly used by send_mail)
• MAIL_TO – destination email address for notifications
• MAIL_FROM – sender email address used in the notification header

Example: configurtion for sSMTP server using the backup script on Synology NAS:

vi /etc/ssmtp/ssmtp.conf

Minimum content for the SMTP gateway without authentication:

SRC="/volume1/data/DS918_1.hbk"
DST="/volumeUSB1/usbshare/"
SMTP="203.0.113.104"
MAIL_TO="hostmaster@example.com"
MAIL_FROM="nas@ds918.local"

Usage

1. Testing the sSMTP configuration with email sending can be done with this command.

echo -e "From: nas@ds918.local\nTo: hostmaster@example.com\nSubject: Test\n\nTest von DS918" | /bin/ssmtp hostmaster@example.com

2. Make sure the script is executable:

chmod +x copy2usb.sh

3. Run the script manually:

./copy2usb.sh

4. Optionally schedule it with cron or Synology Task Scheduler to run regularly.

A task is created in the DSM Task Scheduler, Go to Control Panel > Task Scheduler.

Expected behavior

• If the source path does not exist, the script exits with code 1 and sends a failure email.
• If the destination USB mount is not reachable, it exits with code 2 and sends a failure email.
• If the copy command returns success but the copied destination is not verifiable, it sends a warning email.
• If the copy succeeds and the destination file or folder exists, it sends a success email.

Requirements

• bash
• cp
• ssmtp configured and available at /bin/ssmtp

Notes

• The script currently uses cp -rf, which overwrites existing files and copies recursively.
• The SMTP variable is defined for configuration consistency, but send_mail() relies on the /bin/ssmtp command and does not directly use the variable in this version.