What is the best way to obtain an exact copy download?-->wrong md5 after downloading 5.3dsc1,2=(

[cape canaveral]

On Mon, 8 Nov 2004 12:02:13 +0200, Giorgos Keramidas


<keramida at ceid.upatras.gr> wrote:
> On 2004-11-08 00:41, Mark Jayson Alvarez <jay2xra at yahoo.com> wrote:
> > Good day!
> >   After downloading disc1 and disc2 of freebsd 5.3, my boss told me to
> > verify the download using md5.
>
> Good thinking.
>
> > And to my surprise, none of those two iso's have the same md5 as that
> > of the md5 written in CHECKSUM.md5.
>
> Some times, if you start downloading an ISO image while it is still being
> uploaded to the ftp-master server or while a mirror still fetches the same ISO
> image from ftp-master, what you get is an incomplete download.  Try comparing
> the sizes of the files on the remote server after a while.  If it has changed,
> the ISO iamge is still being uploaded to the FTP server; wait a bit and retry.
>
>
>
> > Question:
> >    On the middle of my download, how will I know if I'm still downloading
> > the correct file, that no packet is being dropped and that I will end up in
> > a perfect mirror file download? Do you know any downloading tool that will
> > do just like this? Earlier, I just used the konqueror when I downloaded
> > those ISO's. Is it really that hard to download? We're using E1 modems and
> > our internet connection is quite fast. I'm just thinking, we are still lucky
> > because of this. But how about those people with low bandwidth internet
> > connection?  Do they have a choice?
>
> All this should be handled gracefully by the TCP network.  AFAIK, there is no
> easy way to verify half of a file while it's still being downloaded over FTP.
>
>
>
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> 

One optoin is to use the Bittorrent download - it will do hash checks
of each piece and re-download any which fail.

Another option (if you do not want to re-download both CDs) is to have
someone with known good copies help you recover the existing files.
Two utilities which can do this are zidrav and quickpar.  I doubt very
much that more than 1MB of parity data would be required to repair
these cd images; they are probably off by only a few bytes.

-Aaron