All disks copied from DECRAM$RECOVER.DAT to MDRECOVER.DAT are
    entered as local memory disks with /capacity=0, /persist,
    /nowritebuffered, and /serve status. DECRAM$RECOVER.DAT only
    contains unit numbers 1000 to 1999. This command is used primarily
    during installation to copy DECRAM$RECOVER.DAT disks to
    MDRECOVER.DAT. At startup the DECRAM$RECOVER.DAT is renamed to
    DECRAM$RECOVER.DAT_VMS.