Full backup off Redhat 5.2 and some other issues

[a bv]

Hi,

1.I want to have a full backup of Redhat systems 5.2, 4x,3x  (which
runs some apps mostly squid and qmail) in order if the servers fail
down in order to down. If ill have to re-setup a system with CD/DVD i
would it be the new ones "twins" with the old ones.  So what to
backup/ restore?
2. Not only i have the root password (sorrily) and i didnt setup the
systems. But sometimes some things go wrong. So i want to full monitor
the systems configuration etc changes that i can know if someone
internal is "playing".
3. In a Redhat 5.2 setuped a few months ago has empty boot logs. What
can be the cause and i want to fix it.

Regards