libvirt cannot create default network

Question

I can't start the default network for libvirt. I get the error in journalctl:

Jun 06 15:22:43 jenia libvirtd[889326]: Unable to create bridge virbr0: Package not installed

I did installed the packages ebtables, bridge-utils and dnsmasq and restarted libvirtd but the problem persists.

Can someone please tell me what package am I missing? I'm using archlinux.

Thanks

P.S.

And the GUI that I'm using (Virtual Machine Manager) gives me:

Error starting network 'default': Unable to create bridge virbr0: Package not installed

Traceback (most recent call last):
  File "/usr/share/virt-manager/virtManager/asyncjob.py", line 75, in cb_wrapper
    callback(asyncjob, *args, **kwargs)
  File "/usr/share/virt-manager/virtManager/asyncjob.py", line 111, in tmpcb
    callback(*args, **kwargs)
  File "/usr/share/virt-manager/virtManager/object/libvirtobject.py", line 66, in newfn
    ret = fn(self, *args, **kwargs)
  File "/usr/share/virt-manager/virtManager/object/network.py", line 75, in start
    self._backend.create()
  File "/usr/lib/python3.8/site-packages/libvirt.py", line 3174, in create
    if ret == -1: raise libvirtError ('virNetworkCreate() failed', net=self)
libvirt.libvirtError: Unable to create bridge virbr0: Package not installed

score 2 · Answer 1 · answered Jun 08 '20 at 11:40

2

That error message comes when libvirt is talking to the kernel I believe. So at a guess, the kernel you have installed is missing the bridge kernel modules. Possibly dmesg might tell you more about what is missing. If this is a custom built kernel, make sure you compiled the bridge support. If this is a distro provided kernel, then look for any extra distro packages related to the kernel.

answered Jun 08 '20 at 11:40

DanielB

1,618
7
7

This happens when the kernel lacks bridge support. The OP should go back to using a distribution kernel instead of the custom kernel, or rebuild it with bridge support. – Michael Hampton Jun 11 '20 at 19:39

score 0 · Answer 2 · answered Dec 24 '21 at 15:25

0

I ran into same problem. I fixed it by

virsh net-start default

as for some reason virt-manager couldn't start it but virsh can. but make sure to check if you have the default network by using virsh net-list --all

answered Dec 24 '21 at 15:25

NotEvil

1
1

score 0 · Answer 3 · answered Jun 04 '23 at 02:39

I got this error after several days using virt-manager, which means it's not lacking of packages issue.

Fixed by: Choose the VM in virt-manager > Edit > Connection details > Virtual networks > default > Tick on "on boot" > Apply

Then restart and it works.

Here is pacman Qi

$ pacman -Qi libvirt                                                                                                              [0]
Name            : libvirt
Version         : 1:9.2.0-1
Description     : API for controlling virtualization engines (openvz,kvm,qemu,virtualbox,xen,etc)
Architecture    : x86_64
URL             : https://libvirt.org/
Licenses        : LGPL  GPL3
Groups          : None
Provides        : libvirt=9.2.0  libvirt.so=0-64  libvirt-admin.so=0-64  libvirt-lxc.so=0-64  libvirt-qemu.so=0-64
Depends On      : libpciaccess  yajl  fuse3  gnutls  parted  libssh  libxml2  numactl  polkit
Optional Deps   : libvirt-storage-gluster: Gluster storage backend
                  libvirt-storage-iscsi-direct: iSCSI-direct storage backend
                  gettext: required for libvirt-guests.service [installed]
                  openbsd-netcat: for remote management over ssh [installed]
                  dmidecode: DMI system info support [installed]
                  dnsmasq: required for default NAT/DHCP for guests [installed]
                  radvd: IPv6 RAD support
                  iptables-nft: required for default NAT networking [installed]
                  qemu-desktop: QEMU/KVM support
                  qemu-emulators-full: Support of additional QEMU architectures
                  lvm2: Logical Volume Manager support [installed]
                  open-iscsi: iSCSI support via iscsiadm
                  swtpm: TPM emulator support

libvirt cannot create default network

3 Answers3