Can you provide the full QEMU command line arguments you're using to reproduce this problem. I tested a guest with the following console config:
<serial type='unix'> <source mode='bind' path='/var/lib/libvirt/qemu/f25-console.sock'/> <log file='/var/lib/libvirt/qemu/f25-console.log'/> <target port='1'/> <alias name='serial1'/> </serial>
and confirmed that the log file gets written, even when no client is connected to the UNIX domain socket.
Can you provide the full QEMU command line arguments you're using to reproduce this problem. I tested a guest with the following console config:
<serial type='unix'> var/lib/ libvirt/ qemu/f25- console. sock'/> var/lib/ libvirt/ qemu/f25- console. log'/>
<source mode='bind' path='/
<log file='/
<target port='1'/>
<alias name='serial1'/>
</serial>
and confirmed that the log file gets written, even when no client is connected to the UNIX domain socket.