Hi Daniel,

# ls /usr/share/libvirt/
cpu_map.xml  libvirtLogo.png  schemas

No "network" folder found

# locate default.xml
/etc/libvirt/storage/default.xml
/etc/libvirt/storage/autostart/default.xml
/home/satimis/.config/libvirt/storage/default.xml
/home/satimis/.config/libvirt/storage/autostart/default.xml
/usr/share/gutenprint/5.2/xml/escp2/inputslots/default.xml


Besides
# ls /etc/libvirt/qemu/networks/
autostart  NAT.xml

# ls /etc/libvirt/qemu/networks/autostart/
NAT.xml

There are 2 NAT.xml file of same content

# cat /etc/libvirt/qemu/networks/NAT.xml
<!--
WARNING: THIS IS AN AUTO-GENERATED FILE. CHANGES TO IT ARE LIKELY TO BE
OVERWRITTEN AND LOST. Changes to this xml configuration should be made using:
  virsh net-edit NAT
or other application using the libvirt API.
-->

<network>
  <name>NAT</name>
  <uuid>2b550fe1-cff0-476e-aabe-f8a239231315</uuid>
  <bridge name='virbr0' stp='on' delay='0'/>
  <mac address='52:54:00:a6:37:e4'/>
  <domain name='NAT'/>
  <ip address='192.168.100.1' netmask='255.255.255.0'>
    <dhcp>
      <range start='192.168.100.128' end='192.168.100.254'/>
    </dhcp>
  </ip>
</network>


# cat /etc/libvirt/qemu/networks/autostart/NAT.xml
<!--
WARNING: THIS IS AN AUTO-GENERATED FILE. CHANGES TO IT ARE LIKELY TO BE
OVERWRITTEN AND LOST. Changes to this xml configuration should be made using:
  virsh net-edit NAT
or other application using the libvirt API.
-->

<network>
  <name>NAT</name>
  <uuid>2b550fe1-cff0-476e-aabe-f8a239231315</uuid>
  <bridge name='virbr0' stp='on' delay='0'/>
  <mac address='52:54:00:a6:37:e4'/>
  <domain name='NAT'/>
  <ip address='192.168.100.1' netmask='255.255.255.0'>
    <dhcp>
      <range start='192.168.100.128' end='192.168.100.254'/>
    </dhcp>
  </ip>
</network>


Regards
SL


-------- Original Message --------
Subject: Re: [libvirt] networking problem
From: "Daniel P. Berrange" <berrange@redhat.com>
Date: Thu, November 02, 2017 9:31 am
To: Stefan Hajnoczi <stefanha@gmail.com>
Cc: msliu@reynoldstocks.com, libvir-list@redhat.com, kvm@vger.kernel.org

On Thu, Nov 02, 2017 at 09:24:22AM +0000, Stefan Hajnoczi wrote:
> On Sun, Oct 29, 2017 at 04:07:09AM -0700, msliu@reynoldstocks.com wrote:
> > I have performed following steps:
> >
> > $ virsh net-destroy default
> > $ virsh net-undefine default
> >
> > Now I couldn't start guest with following warning popup:
> > Error starting domain: Network not found: no network with matching name
> > 'default'
> >
> > Please advise how to re-create 'default' instead of reinstalling all
> > guests.
>
> This is a libvirt question. I have CCed the libvirt mailing list so you
> can continue discussion there.
>
> On Red Hat-based distros try reinstalling the
> libvirt-daemon-config-network package. On Debian-based distros try
> reinstalling the libvirt-daemon-system package. This should restore the
> /etc/libvirt/qemu/networks/default.xml file that you are missing.

No need to re-install those RPMs - Libvirt leaves a copy of the stock XML
file at /usr/share/libvirt/networks/default.xml. So just run

virsh define /usr/share/libvirt/networks/default.xml
virsh start default


Regards,
Daniel
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