Hi p5wizard, the tape was written successfully because the first time I used the same command as now:
tar tvf /dev/rmt/1n, 2 times and finally tar tvf /dev/rmt/1 but always show the message tar: tape read error.
To create the tape I used:
tar cvf /dev/rmt/1n disk1
tar cvf /dev/rmt/1n disk2
tar cvf /dev/rmt/1 disk3
Thanks for all