VMS Help Sys Parameters, PQL_MDIOLM  *Conan The Librarian (sorry for the slow response - running on an old VAX)

    PQL_MDIOLM sets the minimum direct I/O limit for a process
    created by the Create Process ($CREPRC) system service or the
    DCL command RUN (Process).

    PQL_MDIOLM has the DYNAMIC and GEN attributes.