pawel wrote: will have to send data to the tape at a rate of 110MB/s ...... to avoid buffer underrun conditions
From my understanding that statement is true to achieve optimum performance and to reduce wear on the LTO drive.
If you dont reach that data rate the drive will have to stop when the buffer is empty and restart when new data is available in the buffer. And that start/stop operation ads stress to the drive and is not recommended in terms of drive lifetime.
But its not like in the dark ages when a buffer underrun would ruin a CD beeing burnt, its just not optimal.
I have been using a HP LTO5 librarry with a different backup software (HP DataProtector) for the past 5 years and was hardly ever able to reach the native data rate of the drive due to bottlenecks in my source storages. I never experienced any problems, the backuo was simply slower than theoretically possible.
The same is true after moving to a HP LTO6 library last year.
And in addition the newer drives are said to be able to dynamically reduce the write speed, I recommend to double check that with your hardware supplier.