VMS Help JAVA, Qualifiers, /NOASYNCGC  *Conan The Librarian (sorry for the slow response - running on an old VAX)

       /NOASYNCGC
       -noasyncgc

    Turns off asynchronous garbage collection. When activated, no
    garbage collection takes place unless it is explicitly called or
    the program runs out of memory. Normally, garbage collection runs
    as an asynchronous thread in parallel with other threads.