Always consult the list of supported hardware and software on the WebSphere ESB product Web site to determine whether your operating system is supported. The Web site lists all supported operating systems and the operating system fixes and patches that you must install to have a compliant operating system.
See the WebSphere ESB detailed system requirements at http://www.ibm.com/software/integration/wsesb/sysreqs/
If, during installation, the wizard detects that you have insufficient disk space to install WebSphere ESB, you can deselect items to save space. To deselect items, click Custom install in the Type of Install panel.