[TriLUG] Request for Warnings

[Brian A. Henning]

Hi All,
  I currently have a RH7.3 box (P-III 600MHz, 128MB RAM) functioning as
firewall, webserver, MTA, and whatever other various hoops through which I
choose to have it jump now and then.  Following are my current versions of
important stuff:

kernel-2.4.20-20.27
iptables 1.2.8-8.72.3
apache-1.3.27-3
sendmail-8.11.6-27.73

  My goal is to upgrade to FC1.  From what I've heard, it sounds like the
best way to do it would be to step through RH9 on the way.  Now I know that
RH9 is going to want to kick me up to apache-2.something, which is not
backward-compatible with 1.x configuration files.  So that's one headache I
know to expect.  Given the versions of stuff I've mentioned, are there other
non-backward-compatible issues I should be ready to tackle?  I'd like to
prepare for them as much in advance as possibe to minimize total downtime.
My low-quality DNS registrar doesn't afford me backup-mx for my level of
service ($26 a year!  I am thinking of changing, after seeing the recent
thread about other registrars), so there is a functional limit to how long
my server can be offline without causing me additional headaches.

So..  What else should I be ready for?

Thanks for all the help various folks have given me on past issues, by the
way.

Cheers,
~Brian