Amazon Web Services has a great tutorial on how to get MySQL up and running on their persistent storage solution, Elastic Block Store. If you did follow this tutorial on a Fedora instance, however, you may have invalidated your MySQL client config and your PHP configuration.
In the case of the MySQL client, you may observe the following error when trying to access MySQL from the command line:
ERROR 2002 (HY000): Can’t connect to local MySQL server through socket ‘/var/lib/mysql/mysql.sock’
The cause is that everything in /var/lib/mysql was moved to /vol/lib/mysql in the tutorial, including the socket for the client to connect to, so this is easily remedied by adding the following to /etc/my.cnf:
/vol/lib/mysql/mysql.sock
In the case of PHP, you may find that connections can no longer be made to MySQL for the same reason. Simply ensure that the following is set in /etc/php.ini:
Your HTTP daemon will now need to be restarted.
Another option later suggested in the article would involve using symbolic links from the old locations to new ones.