Re: Debian DVD media check
Bhasker, see my comment that is nserted into Andrei's reply
On Sat, Nov 22, 2008 at 11:04:25PM +0200, Andrei Popescu wrote:
> On Sat,22.Nov.08, 14:44:53, Bhasker C V wrote:
> > Hi all,
> >
> > I usually end up having downloaded debian DVDs which I do not know if they
> > downloaded properly. The MD5 sums I do not download (when i use jigdo).
>
> As far as I know jigdo does some additional checks so you should be
> fine.
>
> > Is there a method so that the DVD does a self-test so that i am sure that
> > the DVD is in a good state ? ( sort of a media check ? )
>
> I know Knoppix used to have this, but don't recall about the Debian
> iso's (and don't have one handy to check). Did you read through the
> files on the disk?
>
> > OR
> >
> > is there a method to get the MD5 of a DVD which I have with me ?
>
> md5sum /dev/dvd
This suggestion has worked for me in the past, but recently when installing
lenny, it did not. For some reason, when reading a cd more recent kernels
do not report a of data until a couple of extra block of blank disk are
read. Zeros DO affect an md5 sum so this will not get an md5 sum that matches
the one published for the iso image. Instead you should
1)determine the number of 2048 byte blocks in the original iso image
2)use dd with a data count limit to read in just the right length
3)compute the md5 sum on the data read from CD by dd and compare that
to the published master value.
I don't know why this problem has started happening. With luck, it may not
be happening for you. In which case ignore this excess information. But if
Andrei's method indicates that the CD is a bad copy, don't try burning
another copy. Instead try my method of checking the md5sum.
HTH
>
> > I know that i can get the DVD info from the .disk/info file in the
> > DVD.
> >
> > thanks
> >
> > PS: Please copy me on replies since I am not sure if i am continuing to
> > receive the list mails
>
> Done
>
> Regards,
> Andrei
> --
> If you can't explain it simply, you don't understand it well enough.
> (Albert Einstein)
--
Paul E Condon
pecondon@mesanetworks.net
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