Informix initialization parameters
IBM Informix Dynamic Server maintains its configuration parameters in the ONCONFIG file located in the %INFORMIXDIR%\etc directory on Windows and the $INFORMIXDIR/etc directory on UNIX. The parameters of this file control the server's memory use, the size and number of log files, temporary space, the location of the error logs, and much more.
The IBM Informix Dynamic Server product installation script sets default values for most of the configuration parameters. You would typically increase the values for memory-related ONCONFIG parameters from the defaults as appropriate for your server hardware. For a description of those parameters, see Memory tuning in Informix.
For complete information about IBM Informix Dynamic Server ONCONFIG parameters and how to configure and monitor them, see the chapters on configuration parameters in the IBM Informix Dynamic Server Administrator's Guide and the IBM Informix Dynamic Server Administrator's Reference. The content of these manuals is available in the IBM Informix Dynamic Server v11.10 and v11.50 Information Centers.