Re: [Bug-tar] Possible tar bug

[Paul Eggert]

In <http://lists.gnu.org/archive/html/bug-tar/2010-12/msg00022.html>
you gave this scenario as causing the problem:

  tar -rMf /dev/st0 /home/nas/PC_hry/GTA_IV.rar

with tar responding this way:

  tar: value 15015536189 out of off_t range 0..8589934591
  tar: Exiting with failure status due to previous errors

Unfortunately this is not a complete scenario, since it uses
"tar -r", which appends to an already-existing tar file on /dev/st0.
How was /dev/st0 initialized, before the above command was run?

Here's why I'm asking the question.
I can reproduce the diagnostic as follows:

  echo small >small
  echo some text | dd of=big obs=1 seek=9000000000
  rm -f big*.tar
  tar -c -H ustar -f big1.tar small
  tar --tape-length=100000000c -rM -f big1.tar -f big2.tar -f big3.tar big

With this scenario, tar responds this way:

  tar: value 9000000010 out of off_t range 0..8589934591
  tar: Exiting with failure status due to previous errors

This is clearly a bug in 'tar', because it should not be attempting to
do multivolume dumps with ustar format (POSIX.1-1998), as that format
does not support multivolume dumps.  However, before pursuing a fix I
thought I'd first confirm that something like this is indeed your problem.