The default Lucene Index Server configuration is appropriate for a medium-sized Vibe site. If you have a larger Vibe site, you can change its Lucene Index Server configuration by rerunning the Vibe Installation program, selecting Reconfigure Settings, then selecting Advanced. For instructions, see Changing Your Lucene Index Server Configuration
in Advanced Installation and Reconfiguration
in the OpenText Vibe 4.0.8 Installation Guide.