Active_IO=max-reads

    Specifies the maximum number of read operations from a backup
    device that the RMU Recover command attempts simultaneously. This
    is not the maximum number of read operations in progress; that
    value is a function of active system I/O operations.

    The value of the
    Active_IO qualifier can range from 1 to 5. The default value
    is 3. Values larger than 3 can improve performance with some tape
    drives.