Pavel Sturc thanks for the info. From some seperate discussions I think this is the way to go.
Mark Freer it sounds like this is the easier way to go. I have some experience with upgrades etc. and they don't always go well.
Pavel Sturc do you have scope to take this on in the next few days?
i.e.

• send mail to the mailing list warning of some possible outage
• create the new cluster with fhcap
• update dns
• kill the old cluster with fhcap.