Re: [gentoo-user] Re: Reading a DVD as an ISO image

["José Romildo Malaquias" <j.romildo@gmail.com>]

On Tue, Nov 17, 2009 at 11:15:08AM -0500, Marcus Wanner wrote:
> On 11/17/2009 10:40 AM, Grant Edwards wrote:
> > On 2009-11-17, Jos? Romildo Malaquias <j.romildo@gmail.com> wrote:
> >
> >   
> >> Once I have written a dvd ISO image to a dvd-r disk and then I have
> >> deleted the image from the hard disk. Now I need the image again, but
> >> reading the image from disk does not give me an identical image to the
> >> original one.
> >>
> >> I have used the commands
> >>
> >> $ readcd -vvv dev=/dev/dvd f=image.iso
> >>
> >> and
> >>
> >> $ dd if=/dev/dvd of=image.iso
> >>
> >> With both commands, the resulting image is 99.9% identical to the
> >> original one.
> >>     
> >
> > If you deleted the original, how do you know? the one you're
> > creating from the DVD isn't identical?
> >
> >   
> >> Is there anything I can do to get an image identical to the
> >> original one?
> >>     
> >
> > Since you still seem to have a copy of the original ISO, just
> > use it.
> >   
> My guess is that he has a slow internet connection, he downloaded a 
> large iso, burned it, deleted it, and now wants to get the iso back 
> without downloading it again, but he has access to the checksum/filesize 
> of the original iso from the place he downloaded it, and when he makes 
> an iso, the checksum/filesize does not match.

You guessed almost right. Except by the fact that the original iso was
created by me and transfered to another machine, and now it is lost from
both machines.

Romildo