Mysql default path linux

Note: Do not apply the steps directly in Live Production servers. First test the method in staging or test machines.

It depend upon the scenario on which you are working either you are copying the same data dir within same system or copying it from another server to new server.
The above given eg. is just for an reference.

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How to Change a Default MySQL/MariaDB Data Directory in Linux

After installing the components of a LAMP stack on a CentOS/RHEL 7 server, there are a couple of things you may want to do.

Some of them have to do with increasing the security of the Apache and MySQL / MariaDB, while others may be applicable or not according to our setup or needs.

For example, based on the expected use of the database server, we may want to change the default data directory ( /var/lib/mysql ) to a different location. This is the case when such a directory is expected to grow due to high usage.

Otherwise, the filesystem where /var is stored may collapse at one point causing the entire system to fail. Another scenario where changing the default directory is when we have a dedicated network share that we want to use to store our actual data.

For this reason, in this article, we will explain how to change the default MySQL / MariaDB data directory to a different path on a CentOS/RHEL 7 server and Ubuntu/Debian distributions.

Although we will use MariaDB, the concepts explained and the steps taken in this article apply both to MySQL and to MariaDB unless noted otherwise.

Changing the default MySQL/MariaDB Data Directory

Note: We are going to assume that our new data directory is /mnt/mysql-data . It is important to note that this directory should be owned by mysql:mysql .

# mkdir /mnt/mysql-data # chown -R mysql:mysql /mnt/mysql-data

For your convenience, we’ve divided the process into 5 easy-to-follow steps:

Step 1: Identify Current MySQL Data Directory

To begin, it is worthy and well to identify the current data directory using the following command. Do not just assume it is still /var/lib/mysql since it could have been changed in the past.

# mysql -u root -p -e "SELECT @@datadir;"

After you enter the MySQL password, the output should be similar to.

Step 2: Copy MySQL Data Directory to a New Location

To avoid data corruption, stop the service if it is currently running before proceeding. Use the systemd well-known commands to do so:

------------- On SystemD ------------- # systemctl stop mariadb # systemctl is-active mariadb ------------- On SysVInit ------------- # service mysqld stop # service mysqld status OR # service mysql stop # service mysql status

If the service has been brought down, the output of the last command should be as follows:

Then copy recursively the contents of /var/lib/mysql to /mnt/mysql-data preserving original permissions and timestamps:

# cp -R -p /var/lib/mysql/* /mnt/mysql-data

Step 3: Configure a New MySQL Data Directory

Edit the configuration file ( my.cnf ) to indicate the new data directory ( /mnt/mysql-data in this case).

# vi /etc/my.cnf OR # vi /etc/mysql/my.cnf

Locate the [mysqld] and [client] sections and make the following changes:

Under [mysqld]: datadir=/mnt/mysql-data socket=/mnt/mysql-data/mysql.sock Under [client]: port=3306 socket=/mnt/mysql-data/mysql.sock

Save the changes and then proceed with the next step.

Step 4: Set SELinux Security Context to Data Directory

This step is only applicable to RHEL/CentOS and its derivatives.

Add the SELinux security context to /mnt/mysql-data before restarting MariaDB.

# semanage fcontext -a -t mysqld_db_t "/mnt/mysql-data(/.*)?" # restorecon -R /mnt/mysql-data

Next restart the MySQL service.

------------- On SystemD ------------- # systemctl stop mariadb # systemctl is-active mariadb ------------- On SysVInit ------------- # service mysqld stop # service mysqld status OR # service mysql stop # service mysql status

Now, use the same command as in Step 1 to verify the location of the new data directory:

# mysql -u root -p -e "SELECT @@datadir;"

Step 5: Create MySQL Database to Confirm Data Directory

Login to MariaDB, create a new database and then check /mnt/mysql-data :

# mysql -u root -p -e "CREATE DATABASE tecmint;"

Congratulations! You have successfully changed the data directory for MySQL or MariaDB.

Summary

In this post, we have discussed how to change the data directory in a MySQL or MariaDB server running on CentOS/RHEL 7 and Ubuntu/Debian distributions.

Do you have any questions or comments about this article? Feel free to let us know using the form below – we are always glad to hear from you!

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A Comprehensive Guide to Changing the Default MySQL Data Directory on Ubuntu & Debian

MySQL is a widely-used open-source relational database management system (RDBMS) that powers numerous web applications and services. By default, MySQL stores its data in a predefined directory on Ubuntu and Debian systems, which may not always be suitable for your requirements. For instance, you might want to move the data directory to another location for better performance, security, or to utilize a separate disk or partition.

In this comprehensive guide, we will walk you through the process of changing the default MySQL data directory on Ubuntu and Debian systems, ensuring a smooth transition with minimal downtime.

Step 1: Preparing the New Data Directory

The first step is to create a new directory where you want to store the MySQL data. Ensure that the new location has adequate storage space for your current and future data requirements. Create the new directory using the following command, replacing /disk2/mysql/data with your desired path:

sudo mkdir -p /disk2/mysql/data 

Next, set the ownership and permissions for the new directory to match those of the default MySQL data directory:

sudo chown -R mysql:mysql /disk2/mysql/data sudo chmod 750 /disk2/mysql/data 

Step 2: Stop the MySQL Service

Before making any changes to the MySQL configuration, you must stop the MySQL service to avoid data corruption or loss. Use the following command to stop the service:

sudo systemctl stop mysql 

Step 3: Copy the Existing Data to the New Directory

Now that the MySQL service is stopped, it is safe to copy the existing data to the new directory. To preserve file permissions and ownership, use the rsync command:

sudo rsync -av /var/lib/mysql/ /disk2/mysql/data 

Replace /var/lib/mysql/ with the current MySQL data directory path if it differs on your system.

Step 4: Update the MySQL Configuration

To inform MySQL of the new data directory, you must update the configuration file. Open the MySQL configuration file (typically located at /etc/mysql/mysql.conf.d/mysqld.cnf on Ubuntu and /etc/mysql/mariadb.conf.d/50-server.cnf on Debian) using your preferred text editor:

sudo nano /etc/mysql/mysql.conf.d/mysqld.cnf 

Locate the [mysqld] section and update the datadir and socket options to point to the new directory:

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