Bug#688229: Burning data DVD looks successful but mounting fails with ISOFS: Unable to identify CD-ROM format.

[Thomas Schmitt]

Hi,

>         brasero (libisofs)DEBUG : Processed 2119108 of 2119108 KB (100 %)

It went well, at least as far as libisofs was involved.

So this is not the problem with premature end after 50 %.
And it is not the riddling CD problem, where Brasero CDs are
unreadable, whereas xorriso burned CDs are ok.


> BraseroLibburn Async SYNCHRONIZE CACHE succeeded after 0.8 seconds
> ...
> BraseroLibburn Closing track 01  (absolute track number 1)
> BraseroLibburn Async CLOSE TRACK SESSION succeeded after 0.4 seconds
> BraseroLibburn Closing session
> BraseroLibburn Async CLOSE TRACK SESSION succeeded after 5.3 seconds

These messages stem from libburn.
They indicate that it saw no severe error message from the drive
and that it finished the burn run.
I cannot tell, though, how many data were passed through libburn.


>         [ 9103.816252] ISOFS: Unable to identify CD-ROM format.

What do you get from

  dd if=/dev/sr1 bs=2048 skip=16 count=1 | od -c

With a valid ISO image, the output should begin by

  0000000 001   C   D   0   0   1

and consist of up to 128 lines of text.


What do you get from
  dvd+rw-mediainfo /dev/sr1

(Have medium and tray already loaded. It will not pull in the tray.)


>         $ xorriso -outdev /dev/sr1 -check_media what=disc use=outdev
> ...
>         Media current: DVD-ROM      
>         Media status : is written , is closed
>         A
> Media summary: 1 session, 1059568 data blocks, 2069m data, 0 free
> ...
> xorriso : UPDATE : 1059568 of 1059568 blocks read in 265 s = 5.9xD
> Media checks :        lba ,       size , quality
> Media region :          0 ,        192 , + good
> Media region :        192 ,         16 , + slow
> Media region :        208 ,    1059360 , + good

This xorriso command did not judge whether the medium bears an ISO 9660
filesystem. It only inspected the medium state.

The medium is reported by the drive as DVD-ROM, which is permissible
if it is closed. (Is it a DVD-R ?)
Further the drive did not report any errors when reading the
data blocks. The average reading speed of 5.9x is not overly high
but does not yet indicate a large number of re-tries. No long pauses
were perceived while reading, except the small speed glitch at block 192
which is quite normal.


The following xorriso run would tell more about the recognizability of
ISO 9660 content on the medium:

  xorriso -outdev /dev/sr1 -toc

This run would try to load the directory tree of the ISO image
and issue error messages if there is no proper ISO 9660 on the medium:

  xorriso -indev /dev/sr1

It has to be feared that it will bail out similarly to the mount attempts.


Have a nice day :)

Thomas