5 Easy Steps on Scheduling MySql Database Backup Using Cron

Be it GIT, SVN, Mercurial, CVS or Bazaar – your code is definitely in safe hands. However, websites that have a reasonably large content saved in database or those that interact with the customers, especially the ones receiving orders and tracking payments in an ecommerce platform, like Magento or WooCommerce, need to keep their databases backed up in a compact file in order to enable you to go back to a recent checkpoint, if your database crashes or the website gets hacked.

In this blog, you will learn the steps involved in the configuration of this database backup script on any unix environment, provided you have proper access to the server.

Step 1: Folder and File Creation

Create a folder anywhere, let’s say: /var/backup/, preferably outside the web root to avoid accidental access by anyone besides you.

Now, create a file with executable permission with the name “script.sh” in the folder created earlier.

You need to create another folder, let’s say “db”,where you will be storing your database backups using the following command:

sudo mkdir /var/backup/db

Step 2: Contents of the File

Edit the file “script.sh” that you created in step 1, using vim script.sh or nano script.sh commands (you might need to place sudo in the beginning of the syntax) and place the following content in it:

# (1) set up all the mysqldump variables
DATE=`date +"%d_%b_%Y_%H%M"`
SQLFILE=/var/backup/db/db_backup_${DATE}.sql
DATABASE=<database_name>
USER=<db_user>
PASSWORD=<db_user_password>

# (2) in case you run this more than once a day,
# remove the previous version of the file
unalias rm     2> /dev/null
rm ${SQLFILE}     2> /dev/null
rm ${SQLFILE}.gz  2> /dev/null

# (3) do the mysql database backup (dump)
sudo mysqldump -u ${USER} -p${PASSWORD} ${DATABASE}|gzip > ${SQLFILE}.gz

There are 3 different sections of the contents of this file, let’s have a look:

Section 1:

The first section allows you to set specific values, which suit your environment into variables that are later used in the other two sections of the same file.

i.   DATE

To append the current date & time to the name of the backup file in order to facilitate you in identifying any required file later by just having a look at its name.

ii.   SQLFILE

To let you set the path and file name of the backup file, appending the current date & time (calculated by previous variable) for your ease.

iii.   DATABASE

To specify which database is to be backed up. This is used in the MySQL script for taking database dump/backup.

iv.   USER

To let you set the database username that has access to take a dump of the previous mentioned database.

v.   PASSWORD

To mention the password of the database user that you chose to provide in the previous variable.

Section 2:

The second section helps you remove any database with the same name. You won’t really need this section when you are appending the date and time parameters to your file’s name, but if you are using a general name for the file and you wish your script to override the previous file, then you may include this section to your script.

Section 3:

The third section uses the variables of the first section and executes the mysqldump command to create an exported gzip file. Please note that you need to place the database password in this file that you might not want in some cases, however there exists an alternate method to dump the database without providing the password in the script. To do so, you need to edit the my.cnf file of your mysql configuration. The file might be in 5 or more locations, all are valid because they all load cascading.

• /etc/my.cnf
• /etc/mysql/my.cnf
• $MYSQL_HOME/my.cnf
• [datadir]/my.cnf
• ~/.my.cnf

Edit the file and locate the [mysqldump] section in it.

Now, place the password in this file section just below the user, like the one displayed below:

mysqldump]
quick
quote-names
max_allowed_packet      = 16M
user=root
password=complexPassword

Save this file and restart the mysql service using the following command:

sudo service mysql restart

You won’t need to mention the password in the shell script now.

Step 3: Test to Verify if the Script is Working Correctly

Traverse to the script’s folder:

cd /var/backup/

And execute the following command:

sudo ./script.sh

If your script is working correctly, you should have a backup file created in your /var/backup/db/ folder. If there is no such file, it is likely that you have missed something in the aforementioned commands or you have some user permission restrictions that might require you to use sudo with each command.

Step 4: Scheduling Execution with Cron

Edit the server’s cron with the undermentioned command:

sudo crontab -e

Please note: you can exclude the ‘sudo’ command if you are logged in with root itself or the user you are logged in with has enough permissions to execute cron and create backup.

Enter the following line at the bottom of this file:

0 1 * * * /var/backup/script.sh

The above line in cron will run at 1:00a.m server time every day. If you want to schedule it differently, you may modify it as per your need.

Step 5: Remove Old Backups to Limit Space Usage on Server

Since the hosting servers provide limited space, we usually prefer to limit logs and backups stored on the server. Therefore, you need to remove older backups that you won’t need in the future.

At the bottom of your backup file, add the following command:

sudo find /var/backup/db/. -mtime +7 -exec rm {} \;

This will delete backups older than 7 days. You can, however, modify the -mtime parameter’s value to make it as per your desired time.

This should work for general websites, however in some cases you need to track changes in the database over a longer period of time. Storing all those database backups on the server requires additional memory that results in high costs. Therefore, my next blog will exclusively be for Amazon AWS users, providing them with useful information on how to move older backups to s3 cloud before deleting them from the server.

That’s it from this blog! I am certain that it will help you in scheduling MySql database backup using cron efficiently.

Please feel free to comment or reach out if you have any questions. In case you need any help with server management, cron setup, installation, upgradation and customization of your Magento or Magento 2 web store, please get in touch with us.

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