[gentoo-amd64] Updating An Unconnected Machine

[Frank Peters]

Hello,

I have Gentoo installed on a machine that has no connection to
the Internet.  The configuration of this machine is very similar
to another machine, which _has_ an Internet connection, also running
Gentoo.  Only the CFLAGS variable differ.

Would it be possible to keep this unconnected Gentoo machine updated
by simply copying the entire portage directory, including distribution
files, from the connected machine?

I need to know what happens after doing "emerge --sync" followed
by "emerge -Du world".  I assume that only the portage directory
is affected, that is, only those directories defined by the
PORTDIR, DISTDIR, PKGDIR, PORT_LOGDIR, PORTDIR_OVERLAY, and
PORTAGE_TMPDIR variables in the file make.conf.  If this is
true, then copying those directories to the the unconnected
machine would allow me to update that machine, using emerge,
in parallel with the conected machine and without needing an
Internet connection.

Would this method be feasible?  Unless I am overlooking some details
of the emerge process, I don't see any problems with it.

Frank Peters