#18 Writing data to DVD-R?

[Anonymous]

Hello Ben,

I have a project where I am trying to write data from a unix file system to DVD-R (as a backup or
archive), and I would like to use the udf format on DVD-R media. I can write the data with the
ISO
9660 format now, but that is stretching the bounds of the ISO format and udf has some big
advantages. I have been part of a thread on this topic in the DVD-DATA list, and one of the
other
members mentioned your tools. He uses them for DVD-RAM, and likes them quite a bit. We took
a
look at your docs and the sources, and didn't find a direct reference to DVD-R. I know that this is
somewhat of a different format (streaming rather than a block write) than what it looks like you
are
doing with the udf tools now, but I think I see some hints in the code and the docs that imply that
there was some thought of adding something for DVD-R.

I don't have linux driver support for the DVD-R combo drive that I have, so I have to create an
image on the linux/solaris machines and then use some Windows software to write the raw
filesystem to the disk. It works. It also gives me a workaround that I might be able to use with
UDF. Is it currently possible with your tools to write a file that contains the UDF file system?
That seems to be a hidden feature in several of the other file system creation tools as a
debugging option. Have you thought about supporting DVD-R drives?

Thanks in advance,
Alan Pence
Systems Administrator
Santa Barbara, CA

[Nobody/Anonymous]

Logged In: NO

Dear Alan,

if you don't mind sacrifying a whole DVD-R for a backup, an image can prolly be made also with these tools and then written to the DVD-R.

A sure way of doing this but bypassing the UDF for linux tools is using cdrecord's `mkisofs -J -R -udf disc.iso <files>' and then write the image to the DVD-R with either `dd' or with the modified cdrecord. AFAIK this image can then be mounted read-only on linux.

An other option is to use `growisofs' that also uses `mkisofs' to create a multi-session disc; i am not sure the current linux UDF support code can mount these though.

With regards,
Reinoud Zandijk
(author of udfclient and NetBSD's UDF support)

[Nobody/Anonymous]

Logged In: NO

With other, words it is (currently) not possible to use mkudffs on a DVD-R?

My burning device obviously does not support burning DVD-RAM (cat /proc/sys/dev/cdrom gives back "Can write DVD-RAM: 0")
Trying to mkudffs --udfrev=0x0150 --lvid=backup --vid=backup --media-type=dvd /dev/pktcdvd/0
gives back "trying to change type of multiple extents".
I was tempted to try it anyway for two reasons:
- First the man page of mkudffs says that there is a media type called dvd, which in my opinion could be both dvd-r and dvd-rw. If this is not the case it would be nice if the information on the man page could be clarified.
- Second, I'm using debian and the udftools package comes with a file called README.Debian.gz and it says:

"Packet writing is possible both with write-once media
(CD-R, DVD+R, DVD-R) and rewritable media (CD-RW, DVD+RW,
DVD-RW). Obviously, with write-once media the free space on the
filesystem will not increase if you delete files"

So i thought it would be possible to do that. If not, please tell me I would ask the package maintainer to clarify this in the readme then.

Cheers

Phil