/sys$common/syshlp/helplib.hlb Sys Parameters, GBLPAGES  *Conan The Librarian (sorry for the slow response - running on an old VAX)

    GBLPAGES sets the number of global page table entries allocated
    at bootstrap time. Each global section requires 1 global page
    table entry per section page, plus 2 entries, with the total
    rounded up to an even number.

    Users with CMKRNL privilege can change this parameter on a
    running system. Increasing the value of this parameter allows
    the global page table to expand, on demand, up to the maximum
    size.

    The default value is sufficient for the images normally installed
    as shared in the system startup command procedures. Once the
    system is running and all global sections are created, you can
    examine the actual requirements with the /GLOBAL qualifier of
    the Install utility (INSTALL) and reduce the value of GBLPAGES
    accordingly. However, do not set the value of this parameter
    too low, because the page table entries use little permanently
    resident memory. If you plan to install many user images as
    shared, or if user programs are likely to create many global
    sections, you must increase the value of this parameter.

    GBLPAGES has the AUTOGEN, DYNAMIC, FEEDBACK, GEN, and MAJOR
    attributes.