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View Full Version : [SOLVED] How come I can't use DD command to make an .ISO Disc Image



OzzyFrank
September 18th, 2009, 05:02 AM
I'm wondering if someone can explain why using DD to create an .ISO disc image ends up with a 0-bytes file?

When I use dd if=/media/cdrom of=whatever.iso I get the following a few nanoseconds later:

dd: reading `/media/cdrom': Is a directory
0+0 records in
0+0 records out
0 bytes (0 B) copied, 0.000390544 s, 0.0 kB/s

It doesn't seem to be the path to the disc drive, as /media/cdrom0 gives the same result, and using /dev/cdrom or /dev/dvd gives me:

dd: opening `/dev/cdrom': No such file or directory

So, obviously /media/cdrom is fine, yet the command does nothing (but produce a blank file).

And YES, I do have a disc in the drive, hehe! Any ideas what I need to do here?? Cheers.

mc4man
September 18th, 2009, 05:21 AM
dd the device

ex.

dd if=/dev/scd0 of=whatever.iso

note that even 1 read error will halt dd

What are you trying to dd?

Edit:
If there may be read errors that you don't mind missing then add to command

dd if=/dev/scd0 of=whatever.iso conv=noerror

If it's an encrypted dvd then the dd above will work, but will probably take a long time

dvddisaster is better for all dumps to .iso than dd, for data disks it will fast skip errors on the 1st. pass. You can run it over again and it will only read the missed sectors. Can be done multiple times.
The default is 1 read try per sector, for a 2nd pass you up to 5, for a 3rd, 10.

For a misuse of dvddisaster to dump an encrypted dvd to .iso see here (cannot be burned, just for hdd playback

http://ubuntuforums.org/showthread.php?p=6365060#post6365060

OzzyFrank
September 18th, 2009, 06:22 AM
Yeah, thanks man, that fixed it. It wouldn't recognise /dev/cdrom (or /dev/dvd) so I just thought the mount point had to be used. Didn't realise my device was actually /dev/scd0 - now I know what to do for programs that want to access /dev/cdrom and can't. Cheers. Frank

PS: Glad the Ubuntu Forums finally reinstated the option to mark threads as [SOLVED] - I could never understand why they thought it was a good idea to remove it in the first place.