I am finally planning to start our oVirt hosted engine upgrade. I am not sure how stable my hosted engine storage is ( it shows wrong status in web GUI ) So I arranged a new shared storage and plan to do a fresh install ( altough I noticed there is also an option to upgrade "hosted-engine --upgrade-appliance" ).

After I installed the oVirt 4 hosted engine on a host node I want to move all my running VMs to the new environment. With VMs at first running on the current data storage domain. My storage domain is FC based.

My idea is to:

1. stop all VMs

2. detach Storage domain on old ovirt 3.6 environment ( and keep data ).

3. import and activate the storage domain on the new ovirt 4 environment.

To prevent any data loss or copy too much data I have the follwoing questions: 

1. Is this storage domain import from 3.6 to 4.0 available?

2. I read I should import all VMs, this means I need to copy all data or is it just a matter of importing a config, so all VM data /image remains on the imported storage domain?

3. When for some reason I want to roll back when I have imported the storage domain without having any VM imported, can I just detach and re-attach the storage domain to the previous 3.6 environment?

If there might be a better path to get my VMs to a clean oVirt 4.0 environment I am glad to hear.

Thanks in advance!

Kind regards,

Paul