Bug 740577

+++ This bug was initially created as a clone of Bug #713728 +++

Description of problem:
When editing a network in virsh ('net-edit default', 'net-destroy/start default') to e.g. add a new MAC/IP static address combo, /var/lib/libvirt/dnsmasq/default.hostsfile seems to lag one "version" behind, i.e. carries combos only from the previous edit. To make the current ones effective, changing an unrelated one (e.g. change a hex digit from upper to lowercase) then destroying/restarting the network helps (the unrelated change is only effective on the next change though).

I haven't found this issue in RH/Fedora Bugzilla, but googling gave me an open ticket on Launchpad for Ubuntu: https://bugs.launchpad.net/ubuntu/+source/libvirt/+bug/584910

Version-Release number of selected component (if applicable):
libvirt-0.8.8-4.fc15.x86_64
libvirt-client-0.8.8-4.fc15.x86_64
libvirt-python-0.8.8-4.fc15.x86_64

How reproducible:
Reproducible

Steps to Reproduce:
1. 'net-edit default', then add a new static DHCP mapping to the default network (e.g. <host mac='FF:FF:EE:EE:DD:DD' ip='192.168.122.254' />)
2. 'net-destroy default'
3. 'net-start default'
4. 'grep FF:FF:EE:EE:DD:DD /var/lib/libvirt/dnsmasq/default.hostsfile'
  
Actual results:
(nothing)

Expected results:
FF:FF:EE:EE:DD:DD,192.168.122.254


BTW, I noticed that destroying/starting the network makes it unusable on running guests without rebooting them (they don't ping, restarting the network service in the guest or equivalent doesn't help). Is that expected/intentional or are there ways to add a new static MAC/IP address combo without having to reboot other running guests?

--- Additional comment from nphilipp on 2011-08-03 09:13:50 EDT ---

Ping?

--- Additional comment from crobinso on 2011-08-03 10:23:30 EDT ---

Laine, any thoughts?

--- Additional comment from laine on 2011-08-03 16:34:58 EDT ---

The problem is that when an active network is re-defined, the new data is stored in network->newDef, but the code that builds the new hosts files uses network->def (the old version of the config). If the network is inactive at the time it's redefined, then the new data is stored directly into network->def, and it takes effect immediately.

I just posted a patch upstream to fix the problem:

https://www.redhat.com/archives/libvir-list/2011-August/msg00181.html