Setting Up the onconfig File

Each instance of the database server must have its own onconfig configuration file. Make a copy of an onconfig file that has the basic characteristics that you want for your new database server. Give the new file a name that you can easily associate with its function. For example, you might select the filename onconfig.acct to indicate the configuration file for a production system that contains accounting information.

Set the ONCONFIG environment variable to the filename of the new onconfig file. Specify only the filename, not the complete path.

In the new configuration file, change the following configuration parameters:

• SERVERNUM

  The SERVERNUM parameter specifies an integer (between 0 and 255) associated with a database server configuration. Each instance of a database server on the same host computer must have a unique SERVERNUM value. For more information, see the section on SERVERNUM in the IBM Informix: Administrator's Reference.

• DBSERVERNAME

  The DBSERVERNAME parameter specifies the dbservername of a database server. It is suggested that you choose a name that provides information about the database server, such as ondev37 or hostnamedev37. For more information, see the section on DBSERVERNAME in the IBM Informix: Administrator's Reference.

• MSGPATH

  The MSGPATH parameter specifies the pathname of the message file for a database server. You should specify a unique pathname for the message file because database server messages do not include the dbservername. If multiple database servers use the same MSGPATH, you cannot identify the messages from separate database server instances. For example, if you name the database server ondev37, you might specify /usr/informix/dev37.log as the message log for this instance of the database server.

• ROOTPATH and ROOTOFFSET

  The ROOTPATH and ROOTOFFSET parameters together specify the location of the root dbspace for a database server. The root dbspace location must be unique for every database server configuration.

  If you put several root dbspaces in the same partition, you can use the same value for ROOTPATH. However, in that case, you must set ROOTOFFSET so that the combined values of ROOTSIZE and ROOTOFFSET define a unique portion of the partition. For more information about ROOTPATH and ROOTOFFSET, refer to the chapter on configuration parameters in the IBM Informix: Administrator's Reference.

You do not need to change ROOTNAME. Even if both database servers have the name rootdbs for their root dbspace, the dbspaces are unique because ROOTPATH specifies a unique location.

You might also need to set the MIRRORPATH and MIRROROFFSET parameters. If the root dbspace is mirrored, the location of the root dbspace mirror must be unique. For information about setting MIRRORPATH, see the IBM Informix: Administrator's Guide.