MySQL ERROR 1005 Can’t create table (errno: 121)

ERROR 1005 (HY000): Can’t create table ‘my_db.my_table’ (errno: 121)

When you get an error like this one, you have only one choice – start cursing the genius who thought that error description is good enough while searching for the real meaning of the dreaded message. I can offer you one more option – that if you are using InnoDB, of course – login to mysql and type

mysql> SHOW INNODB STATUS\G

This will give you a lot of output, including a more clear description of the error you encountered. Good luck.