Import Moodle database to a new server

When you're moving your database to a new server, you'll need to import it using a command line tool. The basic command for this task is:

mysql -h <Server> -u <database user> -p <database> < mybackupfile.sql

Here's how it works: replace <Server> with your server's address, <database user> with your MySQL username, and <database> with the name of the database you're importing. The -p flag will prompt you to enter your password securely. The mybackupfile.sql is the SQL dump file you're importing.

Now, if you're dealing with a hefty database, you might want to keep an eye on how the import is progressing. This can be particularly useful if you're working with large datasets or if you're on a slower network connection. A handy tool for this is pv, which stands for "Pipe Viewer". It gives you a visual representation of the data flow through a pipe, showing you how much has been transferred and how much remains.

To use pv for monitoring your database import, you can tweak the command like this:

pv mybackupfile.sql | mysql -h <Server> -u <database user> -p <database>

In this setup, pv reads the mybackupfile.sql file and pipes it into the mysql command. You'll see a progress bar, the amount of data transferred, and an estimated time to completion. This can be incredibly helpful for managing expectations and troubleshooting any potential issues during the import process.

Before you start, ensure pv is installed on your system. If it's not, you can usually install it with your package manager. For instance, on Debian-based systems like Ubuntu, you'd run sudo apt-get install pv. On Red Hat-based systems, you might use sudo yum install pv.

Remember, importing databases can be resource-intensive, so it's wise to perform these operations during off-peak hours if possible. This minimises the impact on your server's performance and reduces the risk of running into timeouts or other issues.