ISO9660 4GB directory structures boundary limit and growisofs

Paul B Mahol onemda at
Tue Apr 27 21:19:02 UTC 2010

On 4/19/10, Paul B Mahol <onemda at> wrote:
> On 4/19/10, Tom Evans < at> wrote:
>> On Mon, Apr 19, 2010 at 1:48 PM, Paul B Mahol <onemda at> wrote:
>>> On 4/17/10, Paul B Mahol <onemda at> wrote:
>>>> On Sat, Apr 17, 2010 at 4:31 PM, Tim Kientzle <kientzle at>
>>>> wrote:
>>>>> Paul B Mahol wrote:
>>>>>> It is apparently not possible to make use of -use-the-force-luke=4gms
>>>>>> on FreeBSD when appending new session after 4GB. Mounted disk
>>>>>> afterwards  show nothing.
>>>>>> Should we allow it like linux does?
>>>>> Are you claiming there is a problem when FreeBSD reads such
>>>>> images or a problem with creating such images?  What
>>>>> programs are you using?
>>>> I burn flac files in multiple sessions, each session have separate
>>>> directory, on DVD+R DL MKM/003
>>>> After I used 4gms switch mounted fs shows nothing. (but there is >5GB
>>>> of
>>>> data)
>>>> According to growisofs source BD (bluray) dont need this switch at all
>>>> ...
>>>>> This sounds like a pretty unsurprising 32-bit truncation
>>>>> bug:  the filesystem structures in ISO9660 are all sector
>>>>> numbers so 8TB should be the natural limit (4G sectors
>>>>> times 2k bytes/sector).
>>>> I did not tested this on FreeBSD amd64 yet.
>>> Update: Linux shows all sessions and Windows 7 shows only first one.
>> From the source code of groisofs.c:
>>  * - DVD+R Double Layer support;
>>  * - -use-the-force-luke=4gms to allow ISO9660 directory structures
>>  *   to cross 4GB boundary, the option is effective only with DVD+R DL
>>  *   and for data to be accessible under Linux isofs a kernel patch is
>>  *   required;
>> So I'm guessing it does something non standard, particularly if
>> windows also refuses to see the data.
> That is pretty old, from 2.4 era, it was added after it was found that
> isofs had bug. Windows at least "try" to show something - only one
> session, but fourth and not second session crossed 4GB limit.
> The source also claims that in BD case there is no need for _force_
> switch at all.

Mounting with -norrip shows all sessions.
Kernel displays "RRIP without PX field?" if I try to mount "normal" way.

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