Only problem I registered was the first start of engine on the first upgraded host (that should be step 7 in link above), where I got error on engine (not able to access web admin portal); I see this in server.log(see full attach here https://drive.google.com/file/d/1UQAllZfjueVGkXDsBs09S7THGDF )n9YPa/view?usp=sharing 2017-12-22 00:40:17,674+01 INFO [org.quartz.core.QuartzScheduler] (ServerService Thread Pool -- 63) Scheduler DefaultQuartzScheduler_$_NON_C LUSTERED started. 2017-12-22 00:40:17,682+01 INFO [org.jboss.as.clustering.infinispan] (ServerService Thread Pool -- 63) WFLYCLINF0002: Started timeout-base cache from ovirt-engine container 2017-12-22 00:44:28,611+01 ERROR [org.jboss.as.controller.management-operation] (Controller Boot Thread) WFLYCTL0348: Timeout after [300] seconds waiting for service container stability. Operation will roll back. Step that first updated the service container was 'add' at address '[ ("core-service" => "management"),("management-interface" => "native-interface")]'Adding Vaclav, maybe something in Wildfly? Martin, any hint on engine side?Yeah, I've already seen such error a few times, it usually happens when access to storage is really slow or the host itself is overloaded and WildFly is not able to startup properly until default 300 seconds interval is over.If this is going to happen often, we will have to raise that timeout for all installations.