creating cd/dvd ?

[John Collier]

>Sergejs Svitnevs, already mentioned/suggest me to use k3b, see his post, in this thread

Oops! My bad.

[Matti_Kurkela · Accepted solution]

"dd" can be used to make an image out of a real CD, but it can *not* be used to burn an image onto a blank CDR/CDRW.

The reason is: the burn program must, among other things, read the "pre-groove" of a blank CDR/CDRW to identify the type of the media and handle the Optical Power Calibration (fine-tune the laser power to suit the type of the media) before the actual writing. "dd" just does not know how to do that.

Your numbered questions:
0.) Yes. If the .iso image file has been created with the necessary information for booting (it's an extension of the ISO 9660 CD-ROM standard, called "El Torito"), using that command will create a bootable CD.

1.) "-dao" is preferred for audio CDs, because it allows you to create an audio CD with no 3 seconds of forced silence between the audio tracks.

2.) Hmm, I don't know that. I would guess it depends on whether the BIOS of the computer to be booted understands multi-session CDs or not. I think the following results are possible:

- works as expected

- the boot information of the _first_ session gets used; any later sessions are ignored as regards to the boot functionality. After the OS is started, all the data is accessible as normal.

- does not work at all (buggy/old BIOS gets confused by the multi-session CD)

Note:
When a CD is inserted to the CD-ROM drive or the computer is (re)started, the drive's firmware will automatically and independently read the list of tracks (and sessions, if applicable) on the CD-ROM. During this time, the OS (or BIOS in the boot situation) sees the drive as busy, i.e. not available. With a multi-session CD, this may take noticeably longer than on a single-session CD.

There can be combinations of BIOS and CD-ROM drive that support booting from a multi-session CD in theory, but cannot do it in practice: the extra time required by the drive to read the list of tracks on a multi-session disk may be longer than the BIOS is willing to wait for the drive to become available.

Because this timeout is usually hardcoded into the BIOS, the only way to work around this problem might be to replace the CDROM drive with one that recognizes multi-session CDs faster. This is inconvenient, and might be impossible in some situations.

To make your bootable CD-ROM work on as many models of hardware as possible, I'd recommend creating the bootable CD as a single session disc.

MK

[Maaz]

Millions of Thanks for such a nice help/reply ;)

Regards
Maaz