Other Tape question

Dear All,

I would like to ask where the tape head stands after a tar tvf <dev>? I thought it stands at the end of the current read archive. However if I write more archive to the tape with tar cvf <dev>, rewind and issue: tar tvf <dev> it reads the first archive. If I issue again the same command, the tape completely freeze, the process go to D+ or DL+ state, I can't use it while I reboot the system.

However it works when I use the seek command ( mt -f <dev> fsf <cnt>) between the tar tvf.

I thought when I use the tar tvf to list the contents it goes through the files and using the device nsa0, it remains the end of that archive. So I supposed issued a tar tvf immediately after an other should work without a mt -f <dev> fsf.

So I have two questions:
1) Why is it hang
2) Is there any way to avoid this kind of behavior, if accidentally send two tar one after another? I mean is there any timeout settings somewhere?

thank you very much
If you are always using /dev/nsa0, the tape should not rewind, leaving it at the next available point.
It would stand just beoynd the ending file mark.

What hardware, OS, type of drive do you have? Are they rusty? :)
Might the second file be so small, that the tape misses the file mark, and the 2nd session just keeps looking for data that never comes.