Channel configuration questions (newbie)

I've been rolling my own update process for our lab for some time. I'm
looking at switching to Current, and I have a couple of (hopefully
simple) naive questions:

0. We mirror updates from RedHat regularly, and I plan to continue that
practice. It is not clear (to me) from the installation instructions
whether we need to rebuild some sort of server-side RPM database after
adding newly available updates. (nrh-update looks like it does) Do we?

1. In Brian's Article, he mentioned that there is no need to maintain
distinct "channels" for different architectures. Is this accurate?

I understand that the i386 packages will run on later architectures just
fine, but getting the kernel and lib RPMs right really does help. If all
of the RPMs land in one channel (i.e. one set of directories), is the
up2date client smart enough to sort them out? (Pardon ignorance here --
I don't subscribe under up2date, so I never looked at how channels are
specified in the UI).

2. We have one or two machines with oddball hardware (e.g. Toshiba
Tablet PC) where support hasn't made it into the "official" kernels and
we have build locally enhanced RPMs. We could do locally enhanced
package upgrades a la "red carpet", but in a (probably vain) effort to
minimize divergence from the "standard" packages, I've gotten into the
habit of installing those only on machines where they are really needed.
Is there a way to distinguish between clients and choose channels based
on the previously recorded machine info, or should I create a new
pseudo-channel specifically for those machines?

3. If I go the pseudo-channel route, the obvious thing to do would be to
try configuring the directories such that the Toshiba config would look
like:

	...
	rpm_dirs = /somewhere/redhat-8.0/Toshiba-RPMS
		/somewhere/redhat-8.0/rh8.0-updates
		/somewhere/redhat-8.0/rh8.0-baseline-rpms

while the "normal" machines would just use:

	...
	rpm_dirs = /somewhere/redhat-8.0/rh8.0-updates
		/somewhere/redhat-8.0/rh8.0-baseline-rpms

The idea here would be to override the rh8.0-updates directory by
putting replacements in the Toshiba-specific directory. Is there a
defined search order rule that determines which directory "wins" if two
RPMs in different directories have the same version number, or should I
resolve this by making "red carpet" style intermediate versions (I know
how to do this if need be).


Current looks like very nice work, by the way!


Thanks


Jonathan S. Shapiro
Johns Hopkins University