VDQ : FC5 yum.conf variations

[Beartooth]

I have a Very Dumb Question about yum configuration -- which, I suspect,
is more of a Fedora question than a yum question. (I run only Fedora.)

I run five FC5 machines -- two on my desk all the time, and a testbed
machine often enough to keep updated (all three behind the same KVM
switch); one downstairs on my wife's desk, mostly over ssh; and a laptop
only when I'm upgrading one of my three, and have to have it out from
behind the KVM switch, or perhaps if we have a house guest who needs to
get online while here. All five run behind the same router, directly or
through a switch, when they run at all; and the router is behind a cable
modem. All are set to do yum update nightly, when connected and booted.

I don't count on the automatic updates, however, but also run yum update
from time to time, whenever I have a minute and think of it. Once in a
while one or another machine gets something new, or hits some problem.

I happened to remember just now that I used at one time to do "yum update
kernel" separately from "yum update" -- because, iirc, "exclude=kernel"
was included by default in /etc/yum.conf under each new release of Fedora.

So I thought to look on a couple of them.

Sure enough, I don't see any "exclude=<anything>" anywhere. Sounds like
there must have been a major victory I'm blissfully unaware of, somewhere.

But I do notice some differences, and I wonder if they're things I need to
learn about. The following are present on some machines and not others,
and not afaik by any doing of mine -- or else they result from something I
did so long ago I've forgotten it ...

One machine has a line saying "keepcache=0" and two have nothing of the
sort -- nothing about keepcache at all. (The laptop and the testbed aren't
running at the moment.)

One has a line saying "retries=20" and two have nothing about retries.

Two say "plugins=1" and one says nothing about plugins.

Two say "metadata_expire=1800" and one says nothing about metadata.

Do I need to do anything about any of these differences? Boot up the
quasi-supernumerary machines and check them, too? Or just let well enough
alone?

-- 
Beartooth Staffwright, Wordcrafty Squirreler, Neo-
Redneck Retiree,  Not Quite Clueless FC Power User