rsync - what can it do?

[bob parker]

On Wed, 5 Feb 2003 06:09, Steve Bonds wrote:
> On Wed, 5 Feb 2003, bob parker bob_parker-at-dodo.com.au |Rsync List| wrote:
> > Maybe I'm barking completely up the wrong tree but here goes.
> >
> > I've downloaded a 700meg iso by ftp using a steam powered dial up
> > connection. It took a week and naturally many resumes.
> >
> > Murphy's Law did not take a holiday of course so the md5sum of the
> > downloaded iso does not match the md5sum of the one at the mirror.
>
> If you are downloading RedHat ISOs, make sure you're getting the correct
> version.  There were two versions of 7.3 out there with different MD5SUM
> values.  Some mirrors had one, others had the other.  Really confused me
> for a while.  ;-)
>
> > Can rsync be used to selectively fetch the part or parts of the iso
> > that are in error assuming that the mirror is also an rsync mirror?
>
> Yes.  I've done this for the same thing under quite similar circumstances.
> Rsync does this automagically just by asking it to copy the file.
>
> > How can I tell?
>
> When the rsync is finished, you can tell since the MD5SUM will be what it
> should be.  ;-)  When done the "speedup factor" shows you how much faster
> it went than if it had to send the whole file.  If this factor is 1.0 you
> just copied the whole thing again.  The "--stats" option also gives you
> some interesting info on the transfer.  Using "--progress" will show you
> the effective transfer rate.  If you're only validating that the file is
> the same so far, this transfer rate will be quite high.  (Much higher than
> your modem bandwidth.)
>
> The hard part is finding an anonymous rsync server with the exact same
> ISO.  Be sure to grab the (preferably GPG-signed) MD5SUM from that server
> BEFORE you start and verify it against the one from your original
> server.  Otherwise you'll just be downloading the whole thing again since
> it's a different file.
>
> This goes without saying, but be sure to save a copy of the original
> downloaded file just in case something goes wrong with the rsync.
>
>   -- Steve

Thanks,

The iso I want is Knoppix, I got the iso and its md5 sum from same server and 
directory.