On UNIX, you can use any ODBC driver manager such as iODBC or unixODBC to create an ODBC data source. The ODBC driver manager adds an entry for the ODBC data source definition to the odbc.ini file.
You can also manually add the ODBC data source definition to the odbc.ini file. On UNIX, all ODBC data source definitions are stored in the odbc.ini file. You can add or modify an ODBC data source definition in the odbc.ini file without using the ODBC driver manager interface.
Typically, the odbc.ini file is located in the user /etc directory. For example, for unixODBC, the odbc.ini file is in the following directory:
/usr/local/etc
To verify the location of the odbc.ini file, check the ODBCINI environment variable.