NPAGEVIR defines the maximum size to which NPAGEDYN can be
    increased. If this value is too small, the system can hang.
    If NPAGEVIR is too large, the result is a penalty of 8 bytes
    per extra page.

    For the benefit of OpenVMS systems with limited physical memory,
    AUTOGEN logs a warning message in its report if NPAGEDYN or
    NPAGEVIR exceeds certain percentages of physical memory.

    AUTOGEN limits its own calculated values for NPAGEDYN and
    NPAGEVIR. These calculated values are adequate for most systems.
    If your system requires a larger value, you can override the
    AUTOGEN calculated values by setting higher values for
    MIN_NPAGEDYN and MIN_NPAGEVIR in MODPARAMS.DAT.

    NPAGEVIR has AUTOGEN and GEN attributes.