I've got a fresh MySQL install on a CentOS 4 AMD64 machine, and I've set the datadir in /etc/my.cnf to /home/mysql/mysql/data, which is the mountpoint for an ext3 filesystem on a RAID 10 disk.

Phew, that was a mouthful.

Now, since I have the root of an ext3 filesystem mounted at /home/mysql/mysql/data, there's a lost+found directory there. Seeing this, mysql thinks it's supposed to be a database:
mysql> show databases;
| Database           |
| information_schema |
| lost+found         |
| mysql              |
| test               |
4 rows in set (0.00 sec)
What I'm asking is this: do you know of any way, perhaps some option in my.cnf, to get mysql to ignore a particular directory in its datadir?