column {
    header "^M^" /* Metaspace - Percent Used */
    data (1-((sun.gc.metaspace.capacity - sun.gc.metaspace.used)/sun.gc.metaspace.capacity)) * 100
    align right
    width 6
    scale raw
    format "0.00"
  }

sun.gc.metaspace.capacity is metaspace.committed(), which is wrong, it should be metaspace.reserved() when max space is configured