Hi Gianluca,

are you able to recall or verify which version of ovirt-hosted-engine-setup did you used when you initially created your hosted-engine env?

I suspect that your issue could be somehow related to https://bugzilla.redhat.com/show_bug.cgi?id=1328921 and https://bugzilla.redhat.com/show_bug.cgi?id=1339306 which have been fixed which patch http://gerrit.ovirt.org/57906 for new deployment but not for who deployed before that and than simply upgraded engine rpms over his working engine VM. 

For 4.1 we are thinking at a mechanism to upgrade also engine VM definition when running engine-setup, currently it's not available.

Probably the best option to fix it right now is something like:

- set global maintenance mode

- manually removing the engine VM from the engine DB (to let the auto-import procedure trigger again)

- shutdown the engine VM

- copy your /var/run/ovirt-hosted-engine-ha/vm.conf somewhere

- edit it adding the required devices

- start the engine VM with hosted-engine --vm-start --vm-conf=myvm.conf

- wait for the auto-import procedure to kick in and re-import the engine VM with the additional devices

- exit global maintenance mode

Roy, do you see something simpler to achieve the same result?