Hello,

I’m running an up to date installation of manjaro-plasma. I’ve installed all the dependancies for kvm/qemu to work. The other night I created a virtual machine for windows and installed a trial version of windows 10 pro. The installation was a simple default installation and it went fine I completely updated the vm and even added a cd-rom drive to the vm to install the virtio-win drivers in the the virtual machine. However when I rebooted my pc the vm won’t start because it’s reporting the default newtork device was not found.
This is the error I get when I try to start the vm. Error starting domain: Requested operation is not valid: network ‘default’ is not active

Traceback (most recent call last):
File “/usr/share/virt-manager/virtManager/asyncjob.py”, line 65, in cb_wrapper
callback(asyncjob, *args, **kwargs)
File “/usr/share/virt-manager/virtManager/asyncjob.py”, line 101, in tmpcb
callback(*args, **kwargs)
File “/usr/share/virt-manager/virtManager/object/libvirtobject.py”, line 57, in newfn
ret = fn(self, *args, **kwargs)
File “/usr/share/virt-manager/virtManager/object/domain.py”, line 1330, in startup
self._backend.create()
File “/usr/lib/python3.8/site-packages/libvirt.py”, line 1234, in create
if ret == -1: raise libvirtError (‘virDomainCreate() failed’, dom=self)
libvirt.libvirtError: Requested operation is not valid: network ‘default’ is not active
I’ve made sure the libvirt service is started with : sudo systemctl restart libvirtd.service
An idea what’s going on?

Update: I went to install a linux vm in qemu/kvm. I again used the vm creation wizard and aside from picking the .iso I’d use to install from and the hard drive size I just went with the defaults. After the machine was created and I went to start it a window popped up saying the network wasn’t started and would I like to start networking along with the vm. I selected yes and went through with the install and the vm installed without a hitch. I tried starting the win10 vm and that started as well. So…why isn’t qemu’s networking starting when I start the virtual machine manager?

libvirt networks must be "started" before you can use them. You can set their autostart flag, in which case they get started automatically when libvirt is started.

Normally, the default network has that flag set, but perhaps it's cleared in your case. The command to set it is virsh net-autostart; I don't know how this is done in the GUI.

Thanks for your reply. I typed virsh net-autostart default into the terminal and rebooted to see if it worked and that did the trick. Thank you very much for your help.