Update:solved (feedback to devs)
I am testing restore of backup onto another virtual appliance, firmware and 1.6 verions are updated and everything works in prod today. So restore works okay and then I upgrade and it failes. It seem to come a long way but ant the end it just hangs or stalls with a traceback text.(somewhere some managment board address is missing)…and I cannot find any clue from the text or logfiles so far. Important progress I made was to try and switch the core from cmc to nagios, it then complained about a service group. I deleted that group and rules that used it and then it could run a version 2.0 with nagios as core. Switching to cmc just makes it hang with the same traceback as when I first tried to update. There is a line with warning: before the traceback, it just says failed to look up ipv4 on a host via DNS- will not be monitored correctly.
I have now tried several times and after each patch update.
Update: as I write this I made a change in the test site with nagios as core and when applying the changes it failed and wrote out the name of the culprit. So I deleted the named host and applied ok. After that I could actually change to cmc core and it seem to run normal. So cmc worked fine with that service group configuration and nagios did not, there is a difference but I dont think it was really important. The installation failed on one of my hosts missing “Management board address is not configured” and there it hang. After deleting that host it worked. I have searched the logs but not found that host other than after nagios core failed to apply the changes. Maybe the logging in the update or cmc startup could be improved, I dont know hos I could have found this without nagios core working temporary.