Here's the command to dump the contents of a MySQL database into a text file. Type or paste this command at the unix (shell) prompt:

/usr/local/bin/mysqldump --opt -u $dbuser -p$dbpassword $db > $filename.sql 

Fill in the $ variables with your own (leaving out the $) to create a plain text file with the contents of your database. You can use to reload all or some of your data in the event of accident or emergency. Download it to your computer for safekeeping as a backup! Be careful if your database contains any sensitive personal information… stuff like that should be encrypted before downloading.