Group_Size=interval
    Nogroup_Size

    Specifies the frequency at which XOR recovery blocks are written
    to tape. The group size can vary from 0 to 100. Specifying a
    group size of zero or specifying the Nogroup_Size qualifier
    results in no XOR recovery blocks being written. The Group_Size
    qualifier is applicable only to tape, and its default value is
    device dependent. Oracle RMU returns an error message if this
    qualifier is used and the target device is not a tape device.