In section "24.6.1.1. VFS Tuning" of the EAP 5 Administration and Configuration Guide there is some confusion over two of the properties: jboss.vfs.forceCopy and jboss.vfs.forceVfsJar

For jboss.vfs.forceCopy the guide seems a bit contradictory indicating that the default is both "true" and "false." :

"jboss.vfs.forceCopy - has the options true and false, with the default being false.
This defines how nested jars should be handled. If forceCopy equals true, we create a temporary copy of the nested jar, and re-wire VFS accordingly. If forceCopy equals false, we handle nested jars in-memory, which doesn't create temporary copy, but is more memory consuming. Currently JBoss Enterprise Application Platform forces temporary copy by default.
If the useCopyJarHandler property is used as part of URI query, you can configure force-copy at runtime, per URI root (if it doesn't already exist)."

The intent is that the default in the VFS system is "false" but this is overridden in the Application platform to be "true." However, since the documentation in in the context of EAP configuration, this should just say that the default is "true".

The jboss.vfs.forceVfsJar property probably should not even appear in this section. It is used for selecting between and old and new jar handling implementation. This was put in for development purposes. The old version should not be used by EAP customers (it has problems and it is not covered by Application Platform tests.). Further, the selection is not germane to "Memory usage."