If you are not able to get access to a sugarcrm installation you can reset the admin password directly via the sql interface.

If you run MySQL you probably use the innodb storage engine because it provides a number of advantages over MyIsam.

The official documentation recommends giving 50-80% of your ram to innodb_buffer_pool_size which can easily go above 10 gb because ram is cheap nowadays. The same documentation recommends settings innodb_log_file_size to 25% of innodb_buffer_pool_size meaning this can easily be 2 or more gb.