I read in Wikipedia (http://en.wikipedia.org/wiki/Digital_Data_Storage
) that in a DAT72 tape drive There are two read heads and two write heads. The read heads verify the data that has been written (recorded). If errors are present, the write heads rewrite the data. If so, then is verifying the backup after writing necessary? It seems there is a hardware verify built in. Verifying doubles the time of the backup, halves the life of the tape and requires that the tape drive be cleaned more often. I am wondering what is the standard practice out there?