Progress w/ UDF Filesystem Support in 2.4.0? 8
LionMage asks: "I know Slashdot
covered this a long time ago, but we have a new kernel now, and other things have changed as well. I followed the evolution of the experimental UDF drivers back in the 2.2.x series of Linux kernels, and Ben Fennema seemed to have both read and write support working. He claimed to be able to write to a CD-RW in UDF format, and I tried his drivers with my DVD-RAM drive with some measure of success. Recently, I installed SuSE Linux 7.1 on my machine, and discovered that the DVD-RAM drive was detected as two different devices, a CD-ROM drive and a "CD writer." OK, well, we'll forgive that little transgression. What's interesting is that inserting a DVD-RAM cartridge with data on it will in fact yield positive results when mounted. So clearly, the 2.4.0 kernel has some UDF support in it. (Unless this is a case where SuSE threw in support on a whim.) But I can only mount UDF volumes read-only. What's the point of a DVD-RAM drive under Linux if you can't write to it? A visit to Ben's page showed that little progress has been made recently, and there are no patches for the 2.4 series kernels. Can anyone comment on UDF support in the current Linux kernel, and how it's progressing? Alternately, are there perhaps some other drivers I'm unaware of which allow write support?"
Advantage of Open Source (Score:1)
UDF yes but DVD vob no (Score:1)
Packet writing (Score:3)
What's really needed for UDF CD-RW and DVD-RAM write support is packet writing. That allows you to write data to the disk in little packets instead of a big stream, so you can write files at a time. Problem is, it's not in the kernel yet; Jens Axboe has a relatively old patch for a 2.4.0-test kernel that I gave up trying to apply to even 2.4.0. When fully implemented, packet writing will allow you to mount -w /dev/cdroms/cdrom0 (or the equivalent packet device if it is implemented using a separate device) /cdrom and then work with files on the CD-RW just like normal files -- with reading and writing. Fun? Go yell at people and it'll get implemented.
Why you got a CDROM and CDR for the same device (Score:2)
The `CD ROM' is
The `CD writer' is
UDF and DVD ioctl support is is Linux 2.2.16 or 2.40 or newer. There's some serious bugs in 2.4.1 which mean you`ll want to avoid that particular version.
Since iso9660 bears a similarity to UDF, you can actually mount many DVDs using this driver, but they'll fail when ISO9660 does - after 2 gig.
Re:hi (Score:1)
Hey... I know you! You're the guy that invented pants!
Re:Packet writing works with DVD-RAM (Score:1)
BTW, if you want to create UDF filesystems, you need the UDF utilities which you can get from http://freshmeat.net/projects/udf/ [freshmeat.net]
Re:Packet writing works with DVD-RAM (Score:1)
Ben
UDF status (Score:1)
2.4.X includes both read/write support for UDF based on the 0.8.9.X release.
The latest version is 0.9.3. The 0.9 series made some major write changes, which is why I havn't sent a diff off to Linus.
If you want to use UDF, I'd suggest grabbing the cvs source off of sourceforge and just compiling it as a module. (linux-udf project)
For DVD-RAM, as long as you compile UDF with write support, you should be able to mount it and write to it (after making the filesystem on it - or using a disc with a pre-existing filesystem on it).
For CD-RW, you need packet writing support. I recently gave a shot at porting pktcdvd from Jens Axboe to 2.4.2 and I got it working, but its not especially stable. =) For information on pktcdvd check out the packet-cd project on sourceforge.
Ben