Re: Writing to ISO file again with different Paras creates old version

[Thomas Schmitt]

Hi,

i wrote:
> >    xorriso -indev /dvdbuffer/test.iso -find -- 2>&1 | less

sean loony wrote:
> This works for me too.
> I used Midnight Commander for a quick 'view' inside the iso.

That would be a similar effect as with the Linux kernel and optical media.
The reader is not aware that the superblock of the ISO has changed and
uses the old superblock content which leads to the directory tree of the
first session.

In case of the Linux kernel, one would have to eject and reload the medium
in order to force it to re-assess the new medium state. But this problem
does not affect ISO images in data files, only on optical media.

So Linux command mount should be able to show the younger state with both
directories:

  sudo mkdir /mnt/iso
  sudo mount /dvdbuffer/test.iso /mnt/iso
  find /mnt/iso 2>&1 | less

You may still access the older state after the first session by

  sudo mount -o sbsector=32 /dvdbuffer/test.iso /mnt/iso

The "sbsector=" number can be read from the output of xorriso -toc:

  $ xorriso -outdev /dvdbuffer/test.iso -toc
  ...
  TOC layout   : Idx ,  sbsector ,       Size , Volume Id
  ISO session  :   1 ,        32 ,     12332s , ISOIMAGE
  ISO session  :   2 ,     12384 ,     12345s , ISOIMAGE
  Media summary: 2 sessions, 24677 data blocks, 48.2m data,  471g free

So if a third session would be added, session 2 could still be mounted by
-o sbsector=12384.


> Short: No bug in xorriso, case closed.

That's the best kind of bug.
(Nearly as good are dangerous bugs found before they were able to bite.)


Have a nice day :)

Thomas