On Sat, Aug 1, 2020 at 11:48 AM <thomas@hoberg.net> wrote:

I confirm, I get "qemu-img: /dev/loop0: error while converting qcow2: Could not open device: Permission denied", too.

You've nailed it and Nir has pasted your log into the bug report 1862115.

It seems that actually the problem happens only the first time a host try to make the OVA.

The second time the disk is created ok. In my case it was so and I was able then to import the OVA file into another 4.3.10 environment and run the VM without problems (I only had to change the logical network assigned to the vnic)

So as a temporary workaround you can try to export as OVA selecting hosta and then, after the "silent" failure, try again using the same host and the file should be correctly created

HIH,

Gianluca