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Every time that I need to use a Flash USB drive, SD card or a HDD I must format it and create a partition before using it, such as NTFS, FAT, FAT32, etc. So this makes me raise some doubts:

  1. Why don't I need to do the same with CDs and DVDs?

  2. Operating systems usually do it before burning media without warning me?

  3. What is the file system typically used on CDs and DVDs?

  4. Could I create two or more partitions inside the same DVD?

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4 Answers 4

up vote 16 down vote accepted
  1. "Formatting" is done when you burn the disc. Because the disc is write only (or being rewritten, in the event of a rewrite), the formatting takes place during the LEAD-IN phase as the TOC or Table of Contents. This TOC is completely dependent upon the data you are burning and therefor cannot be done prior to the burn.

  2. Most programs will display "Lead In" or "Burning TOC".

  3. UDF

  4. You can burn mixed mode CDs that include a data portion and an audio portion. However, I believe all of the information for the entire disc is still stored in one TOC.

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Nice, except ISO9660 is still quite common for CDs. –  Dietrich Epp Jan 19 '12 at 2:46
    
Where does JOLIET come from? Codename for ISO9660? –  HaydnWVN Jan 25 '12 at 14:08
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Joliet is an extension of ISO9660 to allow more fexiblility in file naming. See en.wikipedia.org/wiki/Joliet_%28file_system%29 –  Joe Feb 3 '12 at 3:49
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@kinokijuf: But it also says CDFS when you put a plain audio CD in the drive -- one with no ISO 9660 filesystem. Therefore CDFS can't be a name for ISO 9660, at least according to Windows. –  Dietrich Epp Feb 25 '12 at 22:01
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CDFS is just a name used by various hardware and software vendors and has nothing to do with a specific standard or company whatsoever, Dietrich is right for that matter. The standard does not mention CDFS thus it is not its official name and this has nothing to do with Windows or Microsoft... –  Tom Wijsman Feb 26 '12 at 13:17
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The partitioning is done by the burning application. Assuming you are using Windows, because of the NTFS and FAT references, you can use IMGBURN to actually see those processes.

I suggest you to read CDR FAQ and DVDR FAQ, for more information on these mediums.

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They are indeed being formated using UDF.

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Downvoters please explain? –  bamboon Apr 17 '13 at 8:59
    
I'm one of the downvoters. It's a single line answer that doesn't explain much. It does contain a link, and alghouth it links to Wikipedia and in this particular case might not be subject to link rot, using a link as answer is not encouraged here. Finally, the answer is misleading, as UDF is not the only optical media specification out there. –  That Brazilian Guy Apr 23 '13 at 17:33
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Question #4

Yes but would require software to do this.

Here is one example software

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