Hi,
I'm facing similar problem to described here:
https://www.redhat.com/archives/libvirt-users/2016-February/msg00033.html
I got Libvirt pool mounted over netfs and I'm trying to create new volume, with pool.createXML. When format is qcow2, everything works fine. Unfortunately, for raw images libvirt raises error Permission denied. Whole pool is owned by root. Libvirt starts as root user too.

I've tried to change pool's permissions to 777 on filesystem, but i get the same error, only for RAW images. Volume's xml looks like:
<volume>
    <name>{{user.id}}_{{image.id}}</name>
    <source>
    </source>
    <capacity unit='bytes'>{{image.size}}</capacity>
    <target>
        <format type='{{ image.format }}'/>
        <permissions>
            <mode>660</mode>
        </permissions>
    </target>
</volume>

I've tried to create it without defining permissions, but it's the same. Problem exists in Ubuntu Server 16.04 (libvirt from repo) and Raspbian (libvirt in version 1.2.9). Do you know if it is possible solve this problem with this version of libvirt?


--
Maciej Nabożny