You can add custom scripts to the crontab on your QNAP NAS box. I’ll use it to create a timestamp file in a directory that will be synchronized in real time to a off-site NAS. I’ll check at the off-site NAS if the file is periodically updated to be sure the synchronization is working.

List your crontab contents

crontab -l

Adding entries via command-line

echo "1 4 * * * /share/custom/scripts/custom1.sh" >> /etc/config/crontab
echo "40 5 * * * /share/custom/scripts/custom2.sh" >> /etc/config/crontab

Create the required crontab timeformat here: https://crontab.guru

Modifying entries

Do NOT edit crontab the usual way! On a desktop or server distribution, you would edit a user’s crontab with:

crontab -e

However, due to the way the QNAP firmware updates crontab, it will be overwritten on the next reboot. Obviously, you want your automation to survive reboots, so edit the crontab file directly with your text editor:

vi /etc/config/crontab

or

nano /etc/config/crontab

Restart the daemon

When you’re done, reload the crontab file and restart the cron daemon:

crontab /etc/config/crontab && /etc/init.d/crond.sh restart

Example of timestamp file for monitoring purposes

This sample prints the current timestamp to a file. We’ll monitor off-site the last change date of the file.

*/30 * * * * echo $(date -u) > /share/CACHEDEV1_DATA/allgemein/timestamp.txt 2>&1