mkisofs and large files

[Paul Mather]

On Wed, 8 Dec 2004 04:08:12 +0000, RW
<list-freebsd-2004 at morbius.sent.com> wrote:

> I've been trying to burn a single large file (a 4.2 GB encrypted gbde 
> filesystem within a file) to a DVD, but mkisofs tells me the file is too 
> large. 
> 
> I looked on Google and found that mkisofs had a filesize  limit of 2 GB, but 
> this was increased to 4 GB, so I dropped the filesize to 4095 MB, but it 
> still failed, so I guess the version in ports still has the 2 GB limits.

The mkisofs of sysutils/cdrtools has the 2 GB limitation; the mkisofs
installed by sysutils/cdrtools-devel does not.

> Does the development version of cdrtools in ports have the 4 GB limit? If so, 
> how can  I get sysutils/dvd+rw-tools to use the newer version, is it just a 
> matter of deinstalling them both and  changing the dependence in 
> pkgtools.conf? 

The sysutils/dvd+rw-tools port just looks to see if you have a
${LOCALBASE}/bin/mkisofs present.  If not, it will install the
sysutils/cdrtools port.  Because sysutils/cdrtools-devel installs into
the same place as sysutils/cdrtools, if you have the
sysutils/cdrtools-devel port installed then sysutils/dvd+rw-tools will
use its version of mkisofs.

But, I would issue a big caveat about what you are proposing to do: you
may be able to burn the DVD, but it is likely that you will not be able
to access the large (> 2 GB) file under FreeBSD from the burned disc.

I ran into this problem myself.  I wanted to burn a > 2 GB file to DVD
and was able to do this successfully after installing the
sysutils/cdrtools-devel version of mkisofs and using the sysutils/dvd
+rw-tools port.  But, attempts to access the file fail from the mounted
burned DVD.  For example, if you try and ls the file, you'll get
something along the lines of "ls: foo.tgz: Value too large to be stored
in data type" and attempts to access the file will fail.

I believe the problem is that the kernel cd9660 filesystem support in
FreeBSD only understands the older < 2 GB format.  BTW, I could use the
file under Windows XP, and was able to verify the file correct via a MD5
checksum against the original file I burned.  The file on DVD was
unusable under FreeBSD, though.

So, because you might be burning FreeBSD-specific data (GBDE), the
ability to access the burned data under FreeBSD sounds like a necessity.
You should consider the caveat I mentioned, therefore, and perhaps try
and slice your data into < 2 GB pieces.  (DVD-Video slices its video
into < 1 GB pieces.)

Cheers,

Paul.
-- 
e-mail: paul at gromit.dlib.vt.edu

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