Extended Network Block Device (enbd)

• What is it? Linux Journal article by P.T. Breuer, A. Marin Lopez and Artuo Garcia Ares on The Network Block Device A network block device (NBD) driver makes a remote resource look like a local device in Linux, allowing a cheap and safe real-time mirror to be constructed. http://www2.linuxjournal.com/lj-issues/issue73/3778.html
• Network Block Device (TCP version) project description on Sourceforge:
  http://nbd.sourceforge.net/ (Pavel Machek)
• Summary and files Sourceforge: http://sourceforge.net/projects/nbd
  Version 2.0 released 24 March 2002. Note that this merely complements the in-kernel NBD driver.
• Enhanced Network Block Device project by P.T. Breuer. http://www.it.uc3m.es/~ptb/nbd
• Latest versions -- check the mailing list for discussion: ftp://oboe.it.uc3m.es/pub/Programs/
  nbd-2.4.28.tgz TGZ 355 KB 2002.06.09
• ENBD mailing list info page: http://lists.community.tummy.com/mailman/listinfo/enbd
• Latest discussion: http://lists.community.tummy.com/pipermail/enbd/2002/date.html
• Multimedia for Linux - DVD: http://www.multimedia4linux.de/dvdmodule.html
• DVD CSS Encryption cracked: http://www.firstlight.net/~clarka/decss/
• Linux DVD CSS ioctls information: http://andrewtv.org/linux-dvd/index.jsp
• High-volume data management: http://www.linux-ha.org/

Related pages

• DVD
• Mplayer

Background history

Here is an exchange from the mplayer list on 9-10 June 2002:

If it's possible to define a DVD drive in such a way that programs running on a remote computer can see it even when it's not mounted, that would be great. Does anybody know if this is possible?

I mailed with the author of nbd about 3 month ago as I did want to do the same with the DVD-ROM in my server, but he told me direct hardware access wouldn't work. So the only possibility seems to be mounting DVD with NFS and using old libcss-style ...

Rene

Hi Rene,

The NBD idea is just what I was looking for. Even though the standard nbd doesn't support this, it's very likely that the Extended NBD will now work; they have support for remote ioctls (http://www.it.uc3m.es/~ptb/nbd/). For details, see the on-going development discussion at http://lists.community.tummy.com/pipermail/enbd/2002/date.html -- they've been spending April and May refining how to mount a remote floppy or a CD-ROM.

I'm a newbie here and should make it clear at once that I don't know what I'm doing. However, as far as I know, DVD drives simply use CD drivers in Linux. Here, for instance, is what my DVD does on bootup:

hdc: TOSHIBA DVD-ROM SD-M1212, ATAPI CD/DVD-ROM drive
hdc: ATAPI 32X DVD-ROM drive, 256kB Cache, UDMA(33)
Uniform CD-ROM driver Revision: 3.12

Jens Axboe, the Linux CD-ROM driver maintainer, has long since integrated the DVD CSS ioctls into the Linux CD-ROM driver -- has anything changed here?

So it looks to me like we should be able to mount a remotely located DVD player on a local system and play it as if it were local. NBD doesn't even use NFS, as you know; it relies on the IP. I guess an inquiry to the ENBD people is the place to start.

I can't get to this right away, but if anyone tries it (Rene?), or find somebody who has, could they report back?

Cheers,
Peter