We just migrated from NW5.1 to OES2, but are still stuck with ZfD2 which was installed in the tree quite a few years ago. Since we bought the NOWS, we're planning to upgrade to Zen7. But it seems such big upgrade is not officialy supported.
But has anyone attempted upgrade over so many versions at once? Any caveats?
I would also like to set up some testing environment first, but I'm not sure how to get a working copy of current setup. Should I try to install a completely new OES2 server in isolated network segment and then try to restore backup to this server? Or maybe I should rather install a server, add it to a tree, make it a read-write replica, and then unplug from network? Which approach would be better?