Ioannis Vranos wrote:
> John Hearns wrote:
> 
>  > rpm --install --replacepkgs
>  >
>
> 
> OK, but how can I do it automatically, rather than using this manually, 
> rpm after rpm?


rpm -qa   gives a list of all packages installed on the system
Pipe the output of this to to a script which completes the filename with 
a .rpm extension and pipe that to rpm --install --replacepkgs

If you are using a remote http server for the packages you'll have to 
construct a filename of the type
http://rpm-server/directory/filename.rpm




The above answer is a bit flippant.
Does your install manager not allow you to reinstall machines?
We install clusters from an image, so we would just wipe and re-install 
from the original master image.

I can see cases where you would like to reinstall some packages (as I 
say I have done this myself), but ALL of the packages on a system?
There are lots of package dependencies - are you confident that RPM is 
robust enough to handle all of these?
If you suspect a system has been hacked, you should reinstall, from an 
image as above or via a kickstart.
If your think that reinstalling is too difficult, you should seriously 
be thinking about updating your install method to a PXE-based booting 
scheme.

-- 
      John Hearns
      Senior HPC Engineer
      Streamline Computing,
      The Innovation Centre, Warwick Technology Park,
      Gallows Hill, Warwick CV34 6UW
      Office: 01926 623130 Mobile: 07841 231235