Answer by Vinay Vemula for How to shrink/purge ibdata1 file in MySQL

Adding to John P's answer,

For a linux system, steps 1-6 can be accomplished with these commands:

1. mysqldump -u [username] -p[root_password] [database_name] > dumpfilename.sql
2. mysqladmin -u [username] -p[root_password] drop [database_name]
3. sudo /etc/init.d/mysqld stop
4. sudo rm /var/lib/mysql/ibdata1
sudo rm /var/lib/mysql/ib_logfile*
5. sudo /etc/init.d/mysqld start
6. mysqladmin -u [username] -p[root_password] create [database_name]
7. mysql -u [username] -p[root_password] [database_name] < dumpfilename.sql

Warning: these instructions will cause you to lose other databases if you have other databases on this mysql instance. Make sure that steps 1,2 and 6,7 are modified to cover all databases you wish to keep.