Re: [Bug-xorriso] bug with handling symbolic links?

[Joerg Meyer]

Hi Thomas,

Ah OK, I thought the Joliet tree would also automatically be recreated 
by "-changes_pending yes" if found to be present in the previous session.

With -joliet on I get this output from the xorriso run
        [...]
        ISO image produced: 53550 sectors
        Written to medium : 53728 sectors at LBA 2143488
        [...]
and have these numbers
        -rw-r--r-- 1 root root 4390518784 Mar  8 17:13 -find / -sort_lba -exec 
report_lba
        -rw-r--r-- 1 root root 4499898368 Mar  8 17:14 gentoo-201501-1.3.9.iso

>>> 4390518784 / 2048
2143808
>>> (4499898368 - 4390518784)
109379584
>>> (4499898368 - 4390518784) / 2048
53408

So it's now some ~4MB larger than the original estimate

>>> 51709 * 2048
105900032

(I have rerun -find / -sort_lba -exec report_lba on -find / -sort_lba -exec 
report_lba just to be sure, medium ist DVD+R.)

Cool to gain more and more understanding of how low-level data storage on 
optical media works ;-)

Thanks & best wishes,
Jörg.


On 08 Mar 2015, at 17:00, Thomas Schmitt <address@hidden> wrote:

> Hi,
> 
>> xorriso -for_backup -dev gentoo-201501-1.3.9.iso -changes_pending yes
>> [...]
>> I think the multisession overhead of 68,747,264 bytes [...] 
>> is about two thirds of what to expect from [...]
>> (51,709 * 2048 = 105,900,032)
> 
> That's very suspicious. Hrmmm ....
> 
> ... a few days ago you proposed
> 
>>>               -joliet on -volid test-rebuild \
> 
> My proposal about -dev does not produce a Joliet tree yet.
> If your original ISO was made with -joliet "on", then please
> repeat the experiment with Joliet production
> 
>   dd if=/dev/sr0 bs=2048 of=gentoo-201501-1.3.8.iso
>   xorriso -for_backup -joliet on -dev gentoo-201501-1.3.9.iso \
>           -changes_pending yes
> 
> Check whether the growth is very near to the estimation
> of 105 MB. About everything that's stored between first
> session start and first data file of the session should
> be re-produced in ithe add-on session. First session starts
> at block 0 or block 32, depending on medium type and xorriso
> settings.
> So not much more than 64 KB of difference would be plausible
> here.
> 
> 
> Have a nice day :)
> 
> Thomas
>