what exactly does preupgrade do?

[stan]

Fred Silsbee wrote:
> I've saved emails from posters with conflicting opinions!
> 
> Today is the day...right? Whoopee!
> 
> I want to F9->F10 hopefully without downloading the dvd iso.
> 
> Livecd instructions I already have
> 
> 
>       
> 
There was a link on the Fedora site, I don't have it handy. 
  It explained what it did and how to invoke it.

I used it to upgrade from F7 to F9 in one step.  It worked 
flawlessly, leaving me a few configuration files to examine. 
  It is like the upgrade option of yum, except all of manual 
options are handled automatically.  All of the Fedora 7 
files that had correspondent packages in Fedora 9 had been 
updated to those latest packages.

As someone pointed out here, there is a (potential) issue 
with security.  The packages are checked, but the 
preparation is not.  I think it was susceptible to a man in 
the middle attack, or a corrupted server.  You have to judge 
whether that is too much risk for you.

Hope that helps.