/BITMAP (Alpha/Integrity servers only)

    Displays information about memory use by write bitmaps (WBM) used
    with Host-Based Volume Shadowing (HBVS). If the system parameter
    SHADOWING is set to 0, no information about bitmaps is displayed
    because WBM is used only with HBVS.

    Note that the memory consumption displayed by SHOW MEMORY is
    often greater than that displayed by SHOW DEVICE /BITMAP, which
    displays the exact size (in bytes) of the bitmap. The memory used
    by a bitmap is allocated in units of pages; if a bitmap uses part
    of a page of memory, the rest of that page is unavailable for
    use.