Live Migration failure: Cannot get interface MTU on ‘qbrXXXXXXXX-XX’

Some times, when you are doing a live migration , it will ended up with the following error in the nova-compute.log of hypervisor. The reason for this as follows. The Interface was removed by the user, but LIBVIRT doesnt acknowledged about this. But nova did. So, when nova initiates a live migration, libvirt is looking…

Find out DHCP ports which are in DOWN state

There is two DHCP servers running in each network created under openstack. Each network will have two DHCP servers. The virtual machines in this network is getting IP Address from these DHCP servers. Some times, the status of these DHCP ports shows down while wer querying them. There is a bug reported in neutron, in…

Understanding dnsmasq

Dnsmasq provides network infrastructure for small networks: DNS, DHCP, router advertisement and network boot. It is designed to be lightweight and have a small footprint, suitable for resource constrained routers and firewalls. It has also been widely used for tethering on smartphones and portable hotspots, and to support virtual networking in virtualisation frameworks. When we…