keeping the old public key (id_rsa.pub) when upgrading Fedora

[Mark Ryden]

Hello,
  I have several fedora machines which I upgrade/reinstall, from time to time.

  I do this by reinstalling Fedora (I know that there is an upgrade
option for Fedora but I prefer to reinstall).
When doing so, the /root/.ssh folder is of course deleted.
Now, on some of these machine, I have a public key which is installed
on several servers to enable me
ssh access to these machines without typing the password.
The public key is generated thus:
ssh-keygen -t rsa
And it generates 2 files:
	id_rsa  and id_rsa.pub
And I paste the contents of id_rsa.pub to the server
/root./ssh/authorized_keys (or  /root./ssh/authorized_keys2).


Any idea if there is a way to keep the id_rsa.pub when reinstalling Fedora ?

(If I try  ssh-keygen -t rsa after reinstall, I am unable to ssh to
these servers.)

Regards,
Mark