Burning data to DVD

General information

DVD burners are available on apollo, odysseus and theseus. There are several different types of writable DVD's. Our writers (Plextor PX-708A, NEC 3500A, NEC3540A) can handle DVD-R, DVD-RW, DVD+R and DVD+RW. The "R" types are write-once media and the "RW" types are rewritable media. Both of them come in "+" and "-" flavor. Everything below is only tested with "+R" and "+RW" media.

Another point to note is that the maximum write speed depends on the medium. In general, media rated for higher speeds are more expensive. A nice aspect of the Plextor drive is that it can write at 8x speed on "+R" media that are only rated at "4x" (at least with the Ritek media I use). This works absolutely flawlessly. A side note: when interpreting DVD read/write speeds, keep in mind that the 1x transfer rate of a DVD is already 9 times that of a CD (1353kB/s vs. 150kB/s). The bottom line is that a DVD holds approximately 4.4GB data, and at 8x speed it takes 7-8 minutes to write that amount.

Step-by-step instructions

  1. Assemble all the data that you want to write to the DVD into a meaningful directory structure. In order to ensure a constant data stream to the DVD drive while writing, it is important to have all this data on a local partition, so that you do not depend on network speed during the burning process (as follows from the previous paragraph, 8x speed corresponds to a transfer rate of 10.8MB/s!). For this purpose, apollo has a partition /images. Create a directory (e.g. mydata) here and store your directory structure there.
  2. Now you are ready to burn the DVD. Insert an empty writable DVD into the drive and use this command:
    growisofs -Z /dev/dvdrecorder -d -J -L -r -v -speed=8 /images/mydata
    The meaning of the options can be found on the manpage of mkisofs. A useful additional option (also described on this manpage) is -graft-points which permits you to relocate directory branches. Also, if you receive an error message about conflicting Joliet filenames, add -joliet-long.
    The -speed=8 is specific for the Plextor PX-708A drive and essentially forces the drive to forget earlier speed settings and burn at the highest speed possible for the current medium (see hardware compatibility notes in dvd+rw-tools homepage below).
  3. When you have ensured that the writing was successful, remove the directory you created (in this example mydata).

If you use DVD+RW media, you can append data to the disk. Use exactly the same growisofs command, except that you have to replace -Z with -M.

Alternative: writing an ISO image

If you already have a complete ISO image, you can write it directly via
growisofs -dvd-compat -speed=8 -Z /dev/dvdrecorder=/images/my_image
where /images/my_image is the name of the image file.
Note: growisofs will continuously report the write speed. As you can see, the write strategy of the Plextor drive is such that it starts at 4x, then soon jumps to 6x and after a while to 8x.
In order to create the actual image, you first use mkhybrid:
mkhybrid -d -J -L -r -o /images/my_image -v data
If "data" is a directory, it will be stripped from the path that is on the DVD. I.e., the contents of "data" will be in the root directory of the DVD.
Warning: do not create image files that contain files that are larger than 2GB (2,147,483,648 bytes). mkhybrid will work fine and the final image file will have the correct file size, but when you attempt to read the resulting DVD (either on Linux or Windows XP) the file will be truncated! This is not a limitation of the filesystem that contains the image file, which can exceed 4GB, but a problem with mkhybrid (mkisofs). For clarity: the total DVD image can be as large as you can fit onto the DVD (> 4GB), but no single file within the image should be larger than 2GB.

Extensive additional information (e.g., regarding compatibility with DVD-ROM drives) can be found on the dvd+rw-tools homepage (local copy).

If you burn an ISO image, growisofs continuously reports the write speed. If this speed is considerably lower than expected, a common problem is that DMA is not turned on for the DVD recorder. In SuSE Linux, start YaST, and select "IDE DMA Mode" under "Hardware". If turned off, set the DMA mode for the DVD recorder to "UltraDMA/33".

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This page was last updated on June 27, 2006.