Make your own backup script in Debian

May 17, 2022

Creating your own backup script on your server is pretty simple. Make sure you know what to backup to have it restored in case you need to.

Requirements

• shell script for automating commands;
• crontab for daily execution;

1. Installing cron and crontab

If you have cron installed by default then you can skip here. If it is not installed, run the following commands to do so.

apt-get update
apt-get install cron

2. Preparing your backup script

We will work in our /home/coded/backups folder and just name the script backup.sh. For my example I want to run some simple zip and mysqldump commands. You can adjust it here for your needs.

To create the file type this:

nano /home/coded/backups/backup.sh

In the file we have this content:

#!/bin/sh
mkdir /home/coded/backups/`date +"%Y%m%d"`
zip -r /home/coded/backups/`date +"%Y%m%d"`/apache-backup.zip /etc/apache2/sites-available
zip -r /home/coded/backups/`date +"%Y%m%d"`/nextcloud-backup.zip /var/www/html/nextcloud
mysqldump --single-transaction -h localhost -u YOURUSER -pYOURPASSWORD nextcloud > /home/coded/backups/`date +"%Y%m%d"`/mysql-backup.sql

The date variable will always take the daily date for our folder name. So we first have to create the folder we want to store the files in. Then run zip commands for apache vhosts folder and Nextcloud instance. After that dump the current SQL database with mysqldump.

./backup.sh

The script can be executed with the command above.

3. Give correct premissions to the script

You will most likely get a permission denied error when trying to execute it by hand now. This is because we need to set correct file premissions first.

To check the current permissions type:

ls -l backup.sh

To make the script only executable for the file owner we give it u+x:

chmod u+x backup.sh

To make the script executable by anybody give it +x:

chmod +x backup.sh

4. Automating the process

Now you can try to execute your script by hand the first time. It should do the work. But we don't want to do this everyday. So we adjust the crontab now, type this:

crontab -e

The syntax of the crontab is fairly easy:

*   *   *   *   *   /home/coded/backups/backup.sh

Each fields does have the following meaning:

[Minute]   [Hour]   [Day/Month]   [Month]   [Day/Week]   [Command]

I wanted my script to be executed daily at 12 am, so my cron is as this:

0   12  *   *   *   /home/coded/backups/backup.sh

Save the file and the cron will be active instantly. Your done.

5. Further crontab examples

Schedule a cron job to execute at 2 AM daily:

0   2   *   *   *   /home/coded/backups/backup.sh

Schedule a cron job to execute twice a day:

0   4,16    *   *   *   /home/coded/backups/backup.sh

Schedule a cron job to execute on every minute

*   *   *   *   *   /home/coded/backups/backup.sh

Schedule a cron job to execute on every 10 minutes

*/10    *   *   *   *   /home/coded/backups/backup.sh

Schedule a cron job to execute on selected months

*   *   *   jan,may,aug *   /home/coded/backups/backup.sh

Schedule a cron job to execute on selected days

*   16  *   *   sun,fri /home/coded/backups/backup.sh

Schedule multiple tasks in a single cron job

*   *   *   *   *   /home/coded/backups/backup.sh; /home/coded/backups/backup2.sh

Schedule a cron job to run every 30 seconds

*   *   *   *   *   /home/coded/backups/backup.sh * * * * * sleep 30; /home/coded/backups/backup.sh

Schedule a cron job to execute twice on every Sunday and Monday

*   4,16    *   *   sun,mon /home/coded/backups/backup.sh