datadir

This is the datadir value used by the MySQL instance. The .frm files live here inside subdirectories named after the databases inside the instance.

When a database connection exists, the value is retrieved automatically and overrides any value you specify. This is a crucial parameter for both the MySQL server and MySQL Enterprise Backup.

innodb_data_home_dir

Specifies the directory where InnoDB data files live. Usually the same as datadir, but can be different.

This parameter, together with innodb_data_file_path, determines where the InnoDB data files such as ibdata1, ibdata2, and so on, are situated within the MySQL server.

Typically, you do not need to specify this option, because its value is retrieved automatically using the database connection.

Its value is derived as follows:

innodb_data_file_path

Specifies InnoDB data file names and sizes. Examples:

ibdata1:32M;ibdata2:32M:autoextend
/abs/path/ibdata1:32M:autoextend
innodb-dir/ibdata1:32M:autoextend

When a database connection exists, the value is retrieved automatically and overrides any value you specify.

This parameter together with innodb_data_home_dir determines where the InnoDB data files (such as ibdata1, ibdata2, and so on) live in server repository.

Typically, you do not need to specify this option, because its value is retrieved automatically using the database connection. If no database connection is available, you must specify it.

Whether the initial filename begins with a / character or not, the files are located relative to the innodb_data_home_dir value.

innodb_log_group_home_dir

Specifies where InnoDB logs live within the server repository. Usually the same as datadir, but can be different.

Its value is derived as follows:

innodb_log_files_in_group

Specifies the number of InnoDB log files before being rotated.

Typically, you do not need to specify this option, because its value is retrieved automatically using the database connection. If no database connection is available, you must specify it.

When a database connection exists, the value is retrieved automatically and overrides any value you specify.

innodb_log_file_size

Specifies maximum single InnoDB log file size before switching to next log file. Example: 20M.

Typically, you do not need to specify this option, because its value is retrieved automatically using the database connection. If no database connection is available, you must specify it.

When a database connection exists, the value is retrieved automatically and overrides any value you specify.