Linux versions supported by the Web Server 7.0.9 are listed in Release Notes, see Supported Platforms in Oracle iPlanet Web Server 7.0.9 Release Notes
If you are using a non-supported Linux version, you must perform one of the following tasks to upgrade to the Web Server 7.0.9. You can perform the following task in Java ES environment as well.
Stop the Web Server 6.0 or 6.1 instances.
Upgrade the Linux operating system to one of the Web Server 7.0.9 supported Linux versions.
Migrate the Web Server 6.0 or 6.1 instances to Web Server 7.0.9.
You must upgrade the Linux operating system to one of the supported versions.
Archive the Web Server 6.0 or 6.1 installation directory, including all necessary resources like document root, libraries, and web applications.
Extract the archive to the system running Web Server 7.0.9.
Migrate the extracted Web Server 6.0 or 6.1 instances to Web Server 7.0.9.
Ensure that the directory structure is the same as in Web Server 6.0 or 6.1.