This special parameter is use by VSI and is subject to change. Do
    not change this parameter unless VSI recommends that you do so.

    POOLCHECK is used to investigate frequent and inexplicable
    failures in a system. When POOLCHECK is enabled, pool-checking
    routines execute whenever pool is deallocated or allocated.

    Two loadable forms of SYSTEM_PRIMITIVES.EXE are available at
    boot time. The default image, which contains no pool-checking
    code and no statistics maintenance, is loaded when POOLCHECK
    is set to zero. When POOLCHECK is set to a nonzero value, the
    monitoring version of SYSTEM_PRIMITIVES.EXE, which contains both
    pool-checking code and statistics maintenance, is loaded.

    Setting the SYSTEM_CHECK parameter to 1 has the effect of setting
    POOLCHECK to %X616400FF. For further information about pool
    checking, see the OpenVMS VAX Device Support Manual, (which is
    archived).

    POOLCHECK is a DYNAMIC parameter. However, for a change in its
    value to have any effect, POOLCHECK must be non-0 at boot time
    (to load the monitoring version of SYSTEM_PRIMITIVES.EXE).