Burning CDs and DVDs on the command line

(Debian Wheezy)

It is occasionally useful to know how to perform basic tasks on the command line, especially since most commands are universal across distributions. Below we present instructions for burning and verifying CDs and DVDs on the command line. The following was tested on Debian Wheezy (during testing) using Wodim 1.1.11.

CD

  1. Install wodim using

    sudo aptitude install wodim

  2. Find out which disk is the CD drive using

    wodim --devices

    Example output:

    wodim: Overview of accessible drives (1 found) :
-------------------------------------------------------------------------
0  dev='/dev/sg1'  rwrw-- : 'SONY' 'CD-RW  CRX320E'
-------------------------------------------------------------------------

    In this document, we will use /dev/sg1 as the CD drive from now on.

  3. Insert the CD into the computer. If Debian automatically mounts the CD, then you must unmount it (we will explain how). First, find where the disk is mounted; on Gnome, a file window may open, in which case you can just hit Ctrl-l to see the location. On Debian, it is most likely located somewhere in the /media directory. If you cannot find it there, it may not have even mounted, in which case you may skip this step and the next step.

    In this document, we will assume the CD automatically mounted at /media/cdrom0 from now on.

  4. Unmount the CD (but not eject it) using

    sudo umount /media/cdrom0

  5. If your CD is a CD-RW with data already on it: Blank the old image using

    wodim dev=/dev/sg1 blank=fast

  6. Burn the .iso image. We will assume the file is called image.iso.

    Use the command

    wodim -v -dao dev=/dev/sg1 image.iso

    See the manual for wodim for more information. Use man wodim.

  7. Now we must verify whether the image was correctly burned or not.

    Unfortunately there doesn’t seem to be any logical way to do this.

    Here is what worked:

    dd if=/dev/cdrom bs=2048 conv=sync,notrunc | sha1sum

    that is, if one is to verify using sha1sum. One can of course use md5sum etc.

    The following also worked:

    dd if=/dev/cdrom | sha1sum

    For some reason, none of the following worked:

    dd if=/dev/sg1 bs=2048 conv=sync,notrunc | sha1sum
dd if=/dev/cdrom0 bs=2048 conv=sync,notrunc | sha1sum
dd if=/dev/scd bs=2048 conv=sync,notrunc | sha1sum
dd if=/dev/scd0 bs=2048 conv=sync,notrunc | sha1sum

    During the test run, the SHA1 checksum actually matched the original checksum. (So this method doesn’t completely fail.)

One must remember that CD(-RW)s get old and will eventually cause problems when reading and writing (burning). The CD/DVD drive can also cause problems (i.e., not reading and writing correctly). In short, problems can be software or hardware. It is hoped that this document eliminates any mysteries regarding the former.

DVD

  1. Install the relevant package:

    sudo aptitude install dvd\+rw-tools

  2. Reformat/prepare the DVD:

    dvd+rw-format -force /dev/cdrom

  3. Burn the image; we assume the image file is called image.iso:

    growisofs -dvd-compat -Z /dev/cdrom=image.iso

  4. Check how big the image is:

    ls -ltr image.iso

  5. Suppose the file size returned by the previous command was 123456789. Enter this number in the expression below to find the hash value:

    dd if=/dev/cdrom bs=512 count=$((123456789/512)) | md5sum

    Of course, md5sum can be replaced by any of sha1sum, sha256sum, sha512sum, etc.

  6. Compare the hash from the DVD disc image with the hash from the original ISO image (usually available on the website where you downloaded the image; however if not, md5sum image.iso will also work).

References

The following web pages were especially helpful.