12:06 p.m.
On 22/01/28 10:47PM, Charles Polisher wrote:
...
Seeing as there are no other replies yet, for what it's worth,
on my hypervisor I see similar results for a working system,
and to my knowledge it's all running correctly:
# virsh net-info default
Name: default
UUID: 32ecb497-5a0b-46fd-9786-df4a6ceec9ce
Active: yes
Persistent: yes
Autostart: yes
Bridge: virbr0
Also, this from my library of scripts:
Thank you so much for confirming this!
# ---- cut here ----
#!/bin/bash
#
# Yury V. Zaytsev <yury(a)shurup.com> (C) 2011
# cf.
http://git.zaytsev.net/?p=anubis-puppet.git;a=blob;f=manifests/files/comm...
#
# This work is herewith placed in public domain.
#
# Use this script to cleanly restart the default libvirt network after its
# definition have been changed (e.g. added new static MAC+IP mappings) in
order
# for the changes to take effect. Restarting the network alone, however,
causes
# the guests to lose connectivity with the host until their network
interfaces
# are re-attached.
#
# The script re-attaches the interfaces by obtaining the information about
them
# from the current libvirt definitions. It has the following dependencies:
#
# - virsh (obviously)
# - tail / head / grep / awk / cut
# - XML::XPath (e.g. perl-XML-XPath package)
#
# Note that it assumes that the guests have exactly 1 NAC each attached to
the
# given network! Extensions to account for more (or none) interfaces etc.
are,
# of course, most welcome.
#
# ZYV
#
set -e
set -u
NETWORK_NAME=default
NETWORK_HOOK=/etc/libvirt/hooks/qemu
virsh net-define /opt/config/libvirt/network-$NETWORK_NAME.xml
virsh net-destroy $NETWORK_NAME
virsh net-start $NETWORK_NAME
MACHINES=$( virsh list | tail -n +3 | head -n -1 | awk '{ print $2; }' )
for m in $MACHINES ; do
MACHINE_INFO=$( virsh dumpxml "$m" | xpath /domain/devices/interface[1]
2> /dev/null )
MACHINE_MAC=$( echo "$MACHINE_INFO" | grep "mac address" | cut -d
'"' -f
2 )
MACHINE_MOD=$( echo "$MACHINE_INFO" | grep "model type" | cut -d
'"' -f
2 )
set +e
virsh detach-interface "$m" network --mac "$MACHINE_MAC"
&& sleep 3
virsh attach-interface "$m" network $NETWORK_NAME --mac
"$MACHINE_MAC"
--model "$MACHINE_MOD"
set -e
$NETWORK_HOOK "$m" stopped && sleep 3
$NETWORK_HOOK "$m" start
done
# ---- cut here ----
Thank you so much for sharing your script as well! This is so helpful.
I had my LAN crash yesterday again and I did a few experiments. I tested pinging the hosts
within the LAN from one of my VMs and this wasn't possible (host unreachable). So,
just to clarify, pinging any host within the LAN as well as outside the LAN was not
possible from the VM. The hypervisor WAS able to ping the VM though and I was able to ssh
into the VM from the hypervisor. Hypervisor could not ping any other computer in the LAN
either (same host unreachable error). Name resolution within the LAN was confirmed to be
intact while pinging both by hostname and IP. Just to test it, I destroyed the libvirt
network and restarted it, however, I didn't use several commands used by this script
such as virsh detach/attach-interface and $NETWORK_HOOK, so looking back, it was an
incomplete attempt. This did not solve the problem. My LAN architecture starts with cable
modem that is connected via ethernet cable to my router, which is connected to my 24-port
switch with the same. All computers that were pinged and could not be reached are
connected to the switch via ethernet cables, just like the hypervisor itself. Wireless
access point is also connected to the switch via ethernet cable, and the internet access
was lost on wireless network as well. I use one of my VMs in this hypervisor as the
primary DNS server for my lan through pi-hole and unbound. I believe the loss of internet
is attributable to the loss of bridge network on this VM. Internal network between the
hypervisor and the VM seems to have been preserved somehow (see above). The cable modem
seemed OK and connected by interpretation of its lights during the crash. Rebooting the
hypervisor solved the problem and LAN was again restored without needing to do anything
else. I am stumped. For now, I changed my primary DNS server from the VM to a physical
raspberry pi as a first step. Pi used to be the secondary DNS server, now it is primary.
The VM, on the other hand, is now the secondary DNS server. I am hoping that, if the
libvirt network crashes again(?) I shouldn't lose the whole LAN perhaps by this
change. I am not sure what may be the root cause of this problem. virsh net-info default
during the crash gave the same output as if nothing was wrong with it. Thank you for your
time, I truly appreciate it knowing that it may not be possible to identify what actually
is wrong/failing.
Hakan