[Wikipedia-l] Scheduled global downtime

[Gregory Maxwell]

On 6/4/05, Mark Williamson <node.ue at gmail.com> wrote:
> What I wonder is, in moves like this, why are they all moved at the
> same time? Why not move half, and then after we get _those_ up and
> running again move the other half?

You can't make a subnet appear in multiple places without ugly hackery
and an extra network connection (tunnels, perhaps address translation,
maybe origami routing).

So unless you're also renumbering (which has it's own outage causing
issues) most places are pretty much stuck.

All of this says that while you can avoid downtime it's usually costly
and complex, and if there are problems they often cause more downtime
then you would have had without the the extra measures.