To update Mandriva, go to
easyurpmi, setup epositories for the Mandriva version that you are using (main, contrib, plf and updates). Once thats done, do as root
Code:
#urpmi.update -a
#urpmi --auto-select
All installed packages will be updated.
As for Redht 9, it reached its end of life sometime last year, so there are no more upgrades for it from Redhat. You have to upgrade to Fedora Core or Redhat Enterprise Linux.