On Fri, 2009-02-27 at 10:07 +0200, Dan Kenigsberg wrote:
The real issue is, that in this stage, management may have lost connectivity to the node.
What exactly is the scenario here ? Are you trying to manage any old node as long as it has libvirt installed ? As soon as you need any sort of management-specific code on the node, you might as well implement the logic below in your management code.
if (! newConfigIsWorking()) { virInterfaceDefine(goodConfig); virInterfaceRestart(ifaceName); }
How about having netcf/libvirt be aware of what is a goodConfig (with additional API verb), and back it up somewhere? Any change to to network configuration would have immediate effect, but unless explicitly set as "good", reverted on next boot.
While what you suggest will work in theory (with the minor caveat that reverting to a "good" config can only be triggered by a restart of libvirtd, not a reboot) it is a poor man's workaround for management systems that do not provide proper failsafe functionality. In particular, if you are part of the management system, you have a much better idea (on the node) what it means to have a working network configuration, and can recover from misconfigured network much more gracefully than with the big hammer of a system reboot. David