[libvirt-users] How to disable dnsmasq from starting automatically with libvirtd

Thu Sep 13 05:04:58 UTC 2012

On 2012年09月13日 11:23, Marwan Tanager wrote:
> Hi.
>
> I have a machine with a local DHCP server and a couple of virtual networks and
> I've configured the server for each virtual interface, so that I would be able
> to install VMs on the corresponding subnets using PXE.
>
> The problem is that the two DHCP servers (my local server and dnsmasq) are
> conflicting with each other causing the boot process to either fails or takes
> ages untill a VM can catch the PXE parameters.
>
> Note this output upon starting two VMs on two different subnets:
>
> -----------------------------------------------------------------------------
> tail -n1 -f</var/log/syslog | egrep -i "dhcpd|dnsmasq-dhcp"
> Sep 13 05:11:25 host dhcpd: DHCPDISCOVER from 52:54:00:72:f0:e2 via virbr0
> Sep 13 05:11:25 host dhcpd: DHCPDISCOVER from 52:54:00:2a:e0:a6 via virbr1
> Sep 13 05:11:26 host dhcpd: DHCPOFFER on 192.168.122.194 to 52:54:00:72:f0:e2 via virbr0
> Sep 13 05:11:26 host dhcpd: DHCPOFFER on 192.168.100.107 to 52:54:00:2a:e0:a6 via virbr1
> Sep 13 05:11:27 host dhcpd: DHCPREQUEST for 192.168.122.194 (192.168.122.1) from 52:54:00:72:f0:e2 via virbr0
> Sep 13 05:11:27 host dhcpd: DHCPACK on 192.168.122.194 to 52:54:00:72:f0:e2 via virbr0
> Sep 13 05:11:28 host dnsmasq-dhcp[1882]: DHCPDISCOVER(virbr1) 52:54:00:2a:e0:a6
> Sep 13 05:11:28 host dnsmasq-dhcp[1882]: DHCPOFFER(virbr1) 192.168.100.251 52:54:00:2a:e0:a6
> Sep 13 05:11:28 host dhcpd: DHCPREQUEST for 192.168.100.251 (192.168.100.1) from 52:54:00:2a:e0:a6 via virbr1: unknown lease 192.168.100.251.
> Sep 13 05:11:28 host dnsmasq-dhcp[1882]: DHCPREQUEST(virbr1) 192.168.100.251 52:54:00:2a:e0:a6
> Sep 13 05:11:28 host dnsmasq-dhcp[1882]: DHCPACK(virbr1) 192.168.100.251 52:54:00:2a:e0:a6
> Sep 13 05:11:36 host dnsmasq-dhcp[1882]: DHCPDISCOVER(virbr1) 52:54:00:2a:e0:a6
> Sep 13 05:11:36 host dnsmasq-dhcp[1882]: DHCPOFFER(virbr1) 192.168.100.251 52:54:00:2a:e0:a6
> Sep 13 05:11:36 host dhcpd: DHCPDISCOVER from 52:54:00:2a:e0:a6 via virbr1
> Sep 13 05:11:36 host dhcpd: DHCPOFFER on 192.168.100.107 to 52:54:00:2a:e0:a6 via virbr1
> Sep 13 05:11:38 host dnsmasq-dhcp[1882]: DHCPREQUEST(virbr1) 192.168.100.107 52:54:00:2a:e0:a6
> Sep 13 05:11:38 host dnsmasq-dhcp[1882]: DHCPNAK(virbr1) 192.168.100.107 52:54:00:2a:e0:a6 address not available
> Sep 13 05:11:38 host dhcpd: DHCPREQUEST for 192.168.100.107 (192.168.100.1) from 52:54:00:2a:e0:a6 via virbr1
> Sep 13 05:11:38 host dhcpd: DHCPACK on 192.168.100.107 to 52:54:00:2a:e0:a6 via virbr1
> Sep 13 05:11:53 host dhcpd: DHCPDISCOVER from 52:54:00:72:f0:e2 via virbr0
> Sep 13 05:11:53 host dhcpd: DHCPOFFER on 192.168.122.194 to 52:54:00:72:f0:e2 via virbr0
> Sep 13 05:11:53 host dhcpd: DHCPREQUEST for 192.168.122.194 (192.168.122.1) from 52:54:00:72:f0:e2 via virbr0
> Sep 13 05:11:53 host dhcpd: DHCPACK on 192.168.122.194 to 52:54:00:72:f0:e2 via virbr0
> Sep 13 05:12:00 host dhcpd: DHCPDISCOVER from 52:54:00:72:f0:e2 via virbr0
> Sep 13 05:12:00 host dhcpd: DHCPOFFER on 192.168.122.194 to 52:54:00:72:f0:e2 via virbr0
> Sep 13 05:12:00 host dhcpd: DHCPREQUEST for 192.168.122.194 (192.168.122.1) from 52:54:00:72:f0:e2 via virbr0
> Sep 13 05:12:00 host dhcpd: DHCPACK on 192.168.122.194 to 52:54:00:72:f0:e2 via virbr0
> Sep 13 05:12:03 host dhcpd: DHCPDISCOVER from 52:54:00:2a:e0:a6 via virbr1
> Sep 13 05:12:03 host dhcpd: DHCPOFFER on 192.168.100.107 to 52:54:00:2a:e0:a6 via virbr1
> Sep 13 05:12:03 host dhcpd: DHCPREQUEST for 192.168.100.107 (192.168.100.1) from 52:54:00:2a:e0:a6 via virbr1
> Sep 13 05:12:03 host dhcpd: DHCPACK on 192.168.100.107 to 52:54:00:2a:e0:a6 via virbr1
> Sep 13 05:12:06 host dnsmasq-dhcp[1882]: DHCPDISCOVER(virbr1) 52:54:00:2a:e0:a6
> Sep 13 05:12:06 host dnsmasq-dhcp[1882]: DHCPOFFER(virbr1) 192.168.100.251 52:54:00:2a:e0:a6
> Sep 13 05:12:06 host dnsmasq-dhcp[1882]: DHCPREQUEST(virbr1) 192.168.100.107 52:54:00:2a:e0:a6
> Sep 13 05:12:06 host dnsmasq-dhcp[1882]: DHCPNAK(virbr1) 192.168.100.107 52:54:00:2a:e0:a6 address not available
> Sep 13 05:12:08 host dhcpd: DHCPDISCOVER from 52:54:00:2a:e0:a6 via virbr1
> Sep 13 05:12:08 host dnsmasq-dhcp[1882]: DHCPDISCOVER(virbr1) 52:54:00:2a:e0:a6
> Sep 13 05:12:08 host dnsmasq-dhcp[1882]: DHCPOFFER(virbr1) 192.168.100.251 52:54:00:2a:e0:a6
> Sep 13 05:12:08 host dhcpd: DHCPOFFER on 192.168.100.107 to 52:54:00:2a:e0:a6 via virbr1
> Sep 13 05:12:08 host dnsmasq-dhcp[1882]: DHCPREQUEST(virbr1) 192.168.100.107 52:54:00:2a:e0:a6
> Sep 13 05:12:08 host dnsmasq-dhcp[1882]: DHCPNAK(virbr1) 192.168.100.107 52:54:00:2a:e0:a6 address not available
> Sep 13 05:12:08 host dhcpd: DHCPREQUEST for 192.168.100.107 (192.168.100.1) from 52:54:00:2a:e0:a6 via virbr1
> Sep 13 05:12:08 host dhcpd: DHCPACK on 192.168.100.107 to 52:54:00:2a:e0:a6 via virbr1
> -----------------------------------------------------------------------------
>
> So, is there a way to stop dnsmasq from starting automatically when starting
> libvird? I haven't been able to see any trace of it in the init scripts, and my
> guessing is that it's started not as a service, but in an ad-hoc manner by
> libvirt-bin.
>
> Checking the dependencies of the libvirt-bin package, I've noticed that
> dnsmasq is among them. So, my question is whether, starting dnsmasq
> automatically is something that is hard coded in libvirt-bin or is it just started
> in some other way that I am not aware of?

No, to disable the autostarting of dnsmasq, you need to disable the
autostart of network which drives dnsmasq (named 'default' by default).

% virsh net-autostart --disable default

Then it won't be started automatically along with libvirtd service next
time.

Regards,
Osier