Using apt offline

["Moore, Paul" <Paul.Moore@uk.origin-it.com>]

Hi,
I have a small number of machines which are currently running slink. I'd
like to upgrade them, at least to frozen and possibly even to woody.

The simple answer is apt-get (dist-)upgrade. However, there are a couple of
issues with this. First, I pay for internet downloads, so I want to minimise
download time, and second, at least one of the machines is not connected to
the internet.

The machines' configurations are pretty much identical, so I would like to
download the necessary files *once* and upgrade all the machines offline.
The problem is knowing how to get apt to work this way.

I think that what I could do is

1. apt-get dist-upgrade --download-only on one machine
2. Transfer the downloaded files to all machines
3. apt-get dist-upgrade --no-download on all the machines.

The only difficulty I have is with step (2) - is it enough to transfer the
/var/cache/apt/archives directory? If not, what is the best way?

More generally, what is the best way for me to keep a number of machines
reasonably up to date, given

1. The only CDs I can get are slink (2.1r4) until potato hits the UK CD
market.
2. I have limited network bandwidth.
3. The network bandwidth costs money.

Thanks in advance,
Paul Moore.