virt-manager: Error starting domain

Virtual Machine Manager (virt-manager) doesn’t automatically start your virtual networks. This leads to the following error when starting a vitual machine

Error starting domain: Requested operation is not valid: network 'default' is not active

To solve this error, on Virtual Machine Manger go to Edit->Connection Details->Virtual Networks, select the required network (‘default’ in our case) and press the Start Network button (has a play-button icon). You can avoid having to go through this process by ticking the Autostart checkbox, which will make the network start automatically at boot.

Sharing a folder a windows guest under virt-manager

Sharing data between guest and host system is necessary in many scenarios. If the guest is a Linux system, you can simply add a shared folder that will be automatically mounted. However, this does not work if the guest is Windows. Sometimes, you can simply workaround it by using Samba shares, but in some scenarios network configuration makes it difficult. For example, when using usermode networking, the host machine can’t communicate easily via the network with the guest.

However, there is another way to share folders in virt-manager that actually works for Windows guest – SPICE . The first step is to configure the sharing in virt-manager. In the VM details view, click on “Add Hardware” and select a “Channel” device. Set the new device name to org.spice-space.webdav.0 and leave the other fields as-is.

Now start the guest machine and install spice-webdav on the guest machine. After installing spice-webdav make sure the “Spice webdav proxy” service is actually running (via services.msc).

Now running C:\Program File\SPICE webdavd\map-drive.bat will map the shared folder, which is by default ~/Public. If you encounter the following error

System error 67 has occurred.

the network name cannot be found

It means that the Spice webdav proxy service is not running.

If you want to change the shared folder, you will have to use virt-viewer instead of virt-manager, and configure it under File->Preferences.