8.3-R cannot mount non-BSD burned DVD

Polytropon freebsd at edvax.de
Sun Sep 30 06:12:10 UTC 2012

On Sat, 29 Sep 2012 22:44:24 -0700 (PDT), Jin Guojun wrote:
> This problem seems having been there for a while, but was not pay
> attention to it till now.
> Most DVDs burned under Windows machine cannot be mounted on FreeBSD
> 8.3-R. It gives following error:
> # mount /cdrom
> mount_cd9660: /dev/acd0: Invalid argument
> Some of those DVD can be mount, but no content can be found:
> % df /cdrom
> Filesystem  512-blocks   Used  Avail Capacity  Mounted on
> /dev/acd0      4687968  4687968        0   100%    /cdrom
> % ll /cdrom
> total 4
> dr-xr-xr-x   1 root  wheel  112 Jul 13  2009 ./
> drwxr-xr-x  24 root  wheel  512 Sep 25 23:11 ../
> -r-xr-xr-x   1 root  wheel  135 Jul 13  2009 readme.txt*
> Searched bug report, but did not find related report.
> Does anyone have seen this problem? If so, is any working around for
> this problem?

Cannot confirm that here, reading a various amount of data
and media DVDs. Some of them are in ISO-9660 format, some
of them are UDF. The reader is a cheap LiteOn drive, and
OS version is 8.2-STABLE of last year.

You can check a DVD's content by some tests before attempting
to mount it. First check if they contain a data session, in
this example it's a movie DVD from Russia:

	% cdcontrol info
	Starting track = 1, ending track = 1, TOC size = 18 bytes
	track     start  duration   block  length   type
	    1   0:02.00  222:10.26       0  999776   data
	  170  222:12.26         -  999776       -      -

Okay, one data track. Check _what_ data it is:

	% file - < /dev/acd0
	/dev/stdin: UDF filesystem data (version 1.5) 'NU POGODI'

This media can be mounted like any data DVD, even if we assume
a CD-9660 file system (commonly found on data CDs):

	# mount -t cd9660 -o ro /dev/acd0 /media/dvd
	# df -h /media/dvd
	Filesystem    Size    Used   Avail Capacity  Mounted on
	/dev/acd0     4.1G    4.1G      0B   100%    /media/dvd
	# umount /media/dvd

You could do some similar tests to see where you experience
problems. It's quite possible that the DVDs made in "Windows"
have some problems, e. g. not being closed, or having some
strange data format that doesn't conform to the standard.
Check if they contain a CD-9660 or a UDF file system, and
which version it is. Note that FreeBSD also has a mount_udf
command which could be working for those?

When the CD-9660 file system is used, there are several
extensions that help to deal with restrictions in the original
specification (like file name length or depth of directory
hierarchy). The standard is the RockRidge extension as used
in many operating systems (or, to be correct, by many pre-
mastering and burning tools), but "Windows" uses the "Joliet"
extension. However, FreeBSD can understand both - _if_ they
are properly done.

See "man mkisofs" for details.

Magdeburg, Germany
Happy FreeBSD user since 4.0
Andra moi ennepe, Mousa, ...

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