Making an ISO fails

Olaf Hoyer ohoyer at
Sun Feb 8 10:33:43 PST 2004

On Sun, 8 Feb 2004, Loren M. Lang wrote:

> I have been trying to make an iso of some dvds, an cdroms by just
> copying the file /dev/acd0c, but most of the time it seems to fail with
> an i/o error.  I underestimated the size of a 6G dvd and ran out of
> disk space before it was through, though it got to nearly 4G.  After
> freeing enough diskspace an trying again I couldn't copy more than
> several hundre megs before it got an i/o error.  Removing and
> reinserting the dvd doesn't seem to help.  I can successfully copy the
> dvd by mounting it and copying all the files, but I'd prefer a straight
> copy of the iso image.  I've had various problems doing so with
> different cd/dvds, and I also had a similar problem on linux.  Since
> some cd/dvds work fine, and I can always successfully read it when it's
> mounted, why don't all cd/dvds allow a straight copy of the iso image?


Because of such subtleties like region code, and additional scrambling.
Also there are CD's with copy protection, multisession etc.

when you want to have an exact image of a cd, then you simply use dd
with a blocksize of 2048.
This will give you an exact image, that can be written with cdrecord or
burncd onto the next CD.

With DVD I don't know, never tried personally.

The question ist, what you want with a DVD-rip.
in case you want to copy it, there are some tools in the ports, have a
look at:

copying simply the rawdevice is a bad idea, because it does not
necessarily know about some subtleties that can hinder you...

if its a movie DVD, have also a look at mplayer, with mplayer
--dumpstream you can also dump a .vob file onto your HDD...


Olaf Hoyer        ohoyer at
Fuerchterliche Erlebniss geben zu raten,
ob der, welcher sie erlebt, nicht etwas Fuerchterliches ist.
(Nietzsche, Jenseits von Gut und Boese)

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