Hello, it's me once again. I am afraid the worst scenario was confirmed for me and it looks like there may really be bug directly in tar itself.
This time I've initialized all tapes by copying /dev/null as Paul Eggert adviced me. Than I directly specified the gnu format with --format=gnu switch as folows: sudo tar --format=gnu -cMf /dev/st0 /home/nas/PC_hry/GTA_IV.rar this backup was fine, I wanted to continue with another huge file in folder Zaloha: sudo tar --format=gnu --strip-components=3 -rMf /dev/st0 /home/nas/Zaloha/ Than the error appeared. When I tried to backup all of it at once by specifiing sudo tar --format=gnu --strip-components=3 -rMf /dev/st0 /home/nas/PC_hry/GTA_IV.rar /home/nas/Zaloha/ It was jsut fine. So probably the problem is in appending - I can create archives with huge files, but cannot apend to them with other huge files (bigger than one tape).
