The installation directory is where you want the database server files to reside. The drive on which the directory exists must be formatted using NTFS. IBM Informix software refers to this installation directory as INFORMIXDIR and often uses this value to set the %INFORMIXDIR% environment variable.
However, there is no need to create INFORMIXDIR prior to installation. You can provide the installation directory during the installation process; otherwise, the installation application will create a directory.
The installation program prompts you for different information, depending on the type of installation that you are performing:
If you previously created the INFORMIXDIR directory, this directory is the default installation directory.
If you have already installed a database server, the installation directory is the directory where the database server is installed. If you plan to perform an upgrade or reinstall in the same program group, select this directory as the installation directory.
If you have already installed the database server, the installation directory is the directory where the database server is installed. This installation of the database server has a corresponding Informix Dynamic Server program group on the Start > Programs menu. To install the database server in a second program group, specify an installation directory for the second program group that is different from the installation directory for the first program group. The result is two separate installations of the database server, each installation having its own program group.