Strange permissions on mounted dvd

Jonas Norlander jonorland at
Wed Dec 24 22:35:16 UTC 2008

2008/12/24 Nils Kassube <kassube at>:
> The problem seems to be wrong permissions on the DVD media, not from udev.
> I have checked the commercial DVDs I have and a home made one (made with
> DeVeDe). They all have the same UID/GID 4294967295/4294967295 which is
> just the highest available 32 bit unsigned integer (2^32-1). As there is
> no user known with that UID/GID, ls just shows the number. But all my
> DVDs had permissions dr-xr-xr-x not dr--r--r--. As root doesn't care
> about the missing x bit for directories, the "sudo ls" command was
> successful. Now the question is what type of DVD is it? Is it a
> commercial one or home made? If it is home made, what program was used to
> create it?

I tested with some home burned data DVD he got (so for the record the
ABBA album was not mine) with mp3 files on it and a audio CD. There
where burned with Roxio on Windows XP. And all got the same permission

I checked some different DVD's on my computer and for commercial DVD
movies i got the 4294967295 uid/gid, all other, like home made DVD
movies and data DVD got root as uid/gid for the mountpoint and the
files and dirs on the DVD. For all the different DVD's the permissions
on the mounted DVD is like:
-r-xr-xr-x 1 root root        1478299476 2005-10-14 23:11
dr-xr-xr-x 1 root root       2048 2005-10-14 23:12 AutoRun

and the mount options is:
/dev/scd0 on /media/cdrom0 type udf (ro,nosuid,nodev,utf8,user=jonas)

As far as i understand iso9660 and UDF don't use file permissions if
you don't use the Rock Ridge extensions and don't thinks thats likely.
How can I see if a DVD uses Rock Ridge? For file systems that don't
have file permissions it should be "emulated" in the kernel and
changed with the mount options, right?

I don't think it has anything to do with the DVD media or how it's
burned. I think it has something to do with HAL or mount and some
options passed to those but why and what?.

Thanks for answering my mail.

/ Jonas

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