Hi, > I'm trying to get a better understanding of writing DVDs under Debian. > I'm using a LG 4082B DVD burner, supporting DVD+R(W), > DVD-R(W) and DVD-RAM. It's installed in a machine running a 2.4 kernel, > which has NOT been patched for packet writing, UDF writing or any other > form of DVD support.
No module ide-scsi governing the writer either ? > Most resources suggest using dvdrtools for writing to DVD-R(W) and > dvd+rw-tools for writing to DVD+RW. Both of these tools rely on the use > of ISO9660 filesystems. dvdrtools requires an iso file to be created > before writing to disc, dvd+rw-tools does it on-the-fly through > growisofs. I have had no problems creating discs using these tools. I use with my LG GSA-4082B on Linux 2.4 under ide-scsi emulation either dvd+rw-tools (growisofs 5.21) http://fy.chalmers.se/~appro/linux/DVD+RW/tools/?M=D or cdrecord-ProDVD 2.01b31 ftp://ftp.berlios.de/pub/cdrecord/ProDVD Each of them works for both DVD+RW and DVD-RW. Each of them can be used for writing arbitrary images, not only ISO9660. (I use afio for certain purposes.) With growisofs : growisofs -use-the-force-luke -Z /dev/sr0=/my/image resp.: generate_my_image_to_stdout | \ growisofs -use-the-force-luke -Z /dev/sr0=/proc/self/fd/0 (see man growisofs) With kernel 2.4 and growisofs it seems to be necessary to run the writer under ide-scsi emulation. Therefore the SCSI-address /dev/sr0 rather than /dev/hdc . Before use, DVD-RW need to be formatted. I prefer mode "Restricted Overwrite" despite its quite misleading name : dvd+rw-format -force /dev/sr0 This makes DVD-RW behave much like DVD+RW (for growisofs). With cdrecord-ProDVD (installed as "cdrecord") : cdrecord dev=0,0,0 driveropts=burnfree -data -sao /my/image (see man cdrecord) Without ide-scsi emulation you will have to use prefix ATAPI: (or ATA: ?) with the drive address. Like dev=ATAPI:0,0,0 (see ftp://ftp.berlios.de/pub/cdrecord/README.ATAPI I never tried that myself but know of people who did.) Before re-use with cdrecord-ProDVD, DVD-RW need to be blanked like CD-RW : cdrecord dev=0,0,0 blank=fast DVD+RW get formatted automatically by both growisofs and cdrecord-ProDVD. No special precautions needed to overwrite them. > DVD-RAM discs can have an arbitrary filesystem placed on them and be > mounted. eg. > # mke2fs /dev/cdrom > # mount -t ext2 /dev/cdrom /cdrom > # cp * /cdrom I tried that with Panasonic LM-AF120U3 media. Seems not to work reliably with ide-scsi (MD5 errors when verifying content of a file), is darn slow and larger backups clogg the i/o buffers which then cannot be used for hard disk i/o. Do you get better results without ide-scsi ? > It appears a similar method can also be used with DVD+RW discs, however > I have also tried writing binary streams to DVD+RW discs. For example > # umount /cdrom > # tar -Mcvf /dev/cdrom /some/files > I don't understand why this works, but the resultant disc appears to be > verbatim. Wow. Now if you dump just a raw file to the media cat /my/fat_file >/dev/cdrom and compare it with the original diff /my/fat_file /dev/cdrom 2>&1 | less does it really match ? (At least up to the length of /my/fat_file) > How dependant is the success of the last two methods on the model of DVD > writer used? I understand that such discs would not be readable under > most other operating systems, but would they be readable under Linux on > other machines with generic DVD-ROM drives or DVD writers? Why can > DVD+RW discs be mounted and used that way, but DVD-RW discs can not? The ext2 file system of your DVD-RAM example should mount on old Linux systems. I'm not sure about the ability to use DVD-RAM devices properly. 2.4 and 2.6 kernels should do. (My system does not really support that theory.) Traces in the web indicate that 2.0 and 2.2 were subject to some DVD-RAM related patching. I am willing to bet that you cannot mount on Linux a DVD written with tar cf /dev/cdrom To be mountable, a DVD needs to hold the image of a mountable file system. I am not aware that there is a file system driver for tar-archives in Linux. Nevertheless you should be able to read a tar image with any Unix-style system by just using the CD-ROM device file : tar tvf /dev/cdrom Concerning MS-Windows, Andy Polyakov stated : "tar ztf '\\.\d:' and there're other ways... a." I am still a bit in doubt about the general usability of your writing method. My approach would be tar cvzf - /some/files | \ growisofs -use-the-force-luke -Z /dev/sr0=/proc/self/fd/0 (tar option -M is still a bit obscure to me after reading man and info tar. Is it about end-of-tape handling ?) The methods for reading the tar archive would be the same as above. Have a nice day :) Thomas -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
