Upgrade and cluster

Hello,

there is a OES2015SP1 Cluster with a few GW2014R2 Ressources.

Now I want to do a rolling upgrade of the hole bunch to OES2018 (with
NCS) and GW18. The new cluster nodes are up and running in the old cluster.

I am able to migrate the NSS-Pools to the new nodes (and to it back as
long as I do not upgrade the NSS).

What is the preferred way to get the GW-System to the new nodes and
upgrade them to GW18?

I can install the GW18 parts with the install script to the new nodes
w/o configuration. (I hope that this will create the startup scripts for
SystemD, too.) But will this be enought to go futher through the GW
upgrade process? (Upgrade the DB etc.)

Or should I copy /etc/opt/novell/groupwise/* to the new nodes in front
of the install?

Or is there an other recommended way to do the complete upgrade of OES
and GW. (Is GW2014 supportet to run with OES2018? I think there will be
problems with the startup files.)

Bernd