If you can log into the database then issue the following command:
Code:
mysql> show global variables like 'datadir';
+---------------+-----------------+
| Variable_name | Value |
+---------------+-----------------+
| datadir | /var/lib/mysql/ |
+---------------+-----------------+
1 row in set (0.00 sec)
This parameter tells you where the folder is or should be. If it does not exist make sure that this is created and owned by user running MySQL (typically user mysql).