Hi,

you can read some considerations of mine here in a thread of Mid April, for both multi host and single host:

but they didn't get great replies. possibly the developers are still consolidating a safe upgrade workflow for hosted engine...

and if you read Sandro answer, for single host there is no much hope apart a reinstall.

If you have a multi host lab where to experiment, you can try if my steps to mimic 3.6 -> 4.0 upgrade flow can be valid.

Some of the hard points to verify are:

- host reinstall in CentOS 8 based OS correctly joins the original environment oVirt environment still in 4.3

- current 4.3 engine vm can run on 4.4 host

- "hosted-engine --upgrade-appliance" command exists for 4.4

- what to do if the space on hosted engine storage domain is not sufficient to contains the new engine vm together with the old one

- mixed gluster versions during upgrade don't create problems

Gianluca