Didi,
Both source and destination machines (assuming you are referring to the physical host source and virtual host destination of the migration) are running ovirt-engine 3.5.2.1-1. However, the "source" is on CentOS 6.6, whereas the "destination" is on CentOS 7.1. The source is running postgresql(/-server) 8.4.20, Java 1.7.0_79, httpd 2.2.15. Destination is running postgresql(/-server) 9.2.10, Java 1.7.0.79, jboss-httpd 2.4.6. I'm not sure which over package version is relevant.
The failure occurs after engine-setup, and the web UI doesn't load, and the host reports the engine is not up (I'm not in front of the host, so I don't have the exact language).
Our current setup has 2 physical hosts, ~15 active VMs. Each host has 64GB RAM. Even with all the VM on one host, the utilization is less than 50%. We have another physical storage server, that provides the NFS storage backend to the hosts and VMs. Prior to attempting the hosted-engine migration, I migrated all the VMs to host #1, where the engine was originally installed. I then removed host #2 from the host list via the UI, and performed hosted-engine --deploy on host #2. A few other quirks I encountered:
1. I originally wanted to do "hosted-engine --deploy" on host #1, but that it was unsuccessful due to it complaining the storage connection was busy (or something).
2. I then tried to do "hosted-engine --deploy" on host #2, using the same storage connection path as what I used for host #1 originally. The setup process asked if it was an "additional host", I said no, but later it cannot activate the storage connection.
3. Lastly I did "hosted-engine --deploy" on host #2, but pointing to a different storage connection path, still on the same storage server. This was successful until the I encountered the failure in question.
Thanks,
Haven