Suggest you search the web for backing up mysql databases. Normally, sql databases (no matter which one) are open and must be dumped to a file for backup (which means you need some space to do this.
Found the following at
sixapart.com
You can also create a backup with command line access:
mysqldump -h server -u username -ppassword database > filename
using the appropriate values:
* server - your MySQL server name
* username - your database username
* password - your database password (note there is no space between -p and the password)
* database - your database name
* filename - the name you want for the dump file
It also shows how to restore it.