Virt-Manager isn't going to allow you to start an instance until you enable the default network with virsh. I also feel like it should be mentioned that in order to create / start a network with virsh you need to have linux-headers installed.

--Pyrogon (talk) 17:44 , 30 January 2013 (UTC)Pyrogon

the steps i recommend to follow to ensure virt-manager works properly:

1. libvirtd deamon is up an running with no error in log 2. virtlogd deamon is up and running with no error in log 3. ran the following command once, no error expected. (if network is already active it fails and an error massage apears)

# virsh net-start default

4.at least one virtual network is connected.

--CheesyChocolate (talk) 15:24, 26 April 2023 (UTC)

Announcing network addition:

- This article focuses on using virt-manager and libvirt in user session which has limited networking capabilities (link to https://wiki.libvirt.org/FAQ.html#what-is-the-difference-between-qemu-system-and-qemu-session-which-one-should-i-use)

- Explaining bridge network setup: Setup bridge in libvirt system (requires libvirtd running - suggesting to use/enable the socket instead of having libvirtd running all the time), use the qemu-bridge-helper to be able to use the system bridge in user session. Link to https://wiki.archlinux.org/title/QEMU#Bridged_networking_using_qemu-bridge-helper.

- Link to issue with networking and firewalld https://gitlab.com/libvirt/libvirt/-/issues/215

done

Topas-rec (talk) 10:33, 2 July 2023 (UTC)

QEMU connection does require libvirtd.service running.

I might be wrong but I was getting an error connecting to QEMU without libvirtd.service running:

Unable to connect to libvirt qemu:///system. Failed to connect socket to '/var/run/libvirt/virtqemud-sock': No such file or directory Found the same issue (sorry for reddit link):

https://www.reddit.com/r/VFIO/comments/paj4rv/qemukvm_not_connected_varrunlibvirtqvirtqemudsock/

War (talk) 22:13, 21 June 2023 (UTC)

This article is about libvirt and virt-manager. In these two tools you need to use the system our session URL. System requires root privileges and session does not. See https://wiki.libvirt.org/FAQ.html#what-is-the-difference-between-qemu-system-and-qemu-session-which-one-should-i-use for details.

All in all I would also remove this statement.

Topas-rec (talk) 10:16, 2 July 2023 (UTC)

This is true, you just need to add a connection and select "QEMU/KVM session". It should be noted that network types are limited, but you should have internet right away with the default. Had I known this was an option in the beginning I would have never needed the libvirt services running, nor would I have had to make a network bridge.

This suggestion is a good one. Bhoffman (talk) 20:57, 3 September 2024 (UTC)

After having struggled finding out how to use HostOnly on VMM, as it is not an option like on vmware and virtualbox, I wanted to contribute by making this Headline.

I have just read:

https://bbs.archlinux.org/viewtopic.php?id=181323

And it describes how one should first announce a major edit in the Talk.

Next time I'm going to announce before making an edit.

I hope this is post appropriate. If not it would be nice to write a reason on why my edit was reverted. Fraying7242 (talk) 21:40, 7 May 2025 (UTC)

Under Basic Configuration it might be worth mentioning that libvirt-qemu must have execution privileges on all directories up until the directory you want the VM files to be so virt-manager can run.

For example, Dolphin and Thunar mount other drives under /run/media/<user>, but this directory, by default, does not have execution privilege for others. virt-manager tries to add ACL for itself, but will fail if not run as root; this is the command that it tries to run:

$ setfacl --modify user:libvirt-qemu:x /run/media/<user>

This is required if you want your VMs to be on a second or external drive. The above command can be seen by running virt-manager with --debug. Andz (talk) 17:09, 23 July 2025 (UTC)

I forgot to follow up on this, this udev rule will do the work automatically:

ACTION=="change", SUBSYSTEM=="block", RUN+="/usr/bin/setfacl --modify user:libvirt-qemu:x /run/media/<user>"

- Andz (talk) 05:29, 20 August 2025 (UTC)

The Non root KVM without Socket section says that the user must change the user and group inside /etc/libvirt/qemu.conf, but is it really needed to change the group? Why wouldn't just changing the user suffice? 0xMrRobot (talk) 12:39, 13 March 2026 (UTC)

The Installation section has different instruction for LXC and QEMU. But using socket activation just means that systemd activates the service on demand rather than on boot. Wouldn't using socket activation also work for LXC? 0xMrRobot (talk) 12:42, 13 March 2026 (UTC)