Re: [Libvir] Autostarting guests and networks

On Fri, Feb 16, 2007 at 02:51:07PM +0000, Mark McLoughlin wrote: > Hey, > We need some way to have libvirtd automatically start guests and > networks. > > We had said we should have autostart directories containing config > files of guests/networks which should be autostarted. One problem I see > with that is that we'd need a new API to define autostart configs. > > So, I suggest we add an "autostart" flag to the toplevel element of the > configs. > > We could discuss this one at length and I, for one, don't like using > the XML format as an API like this, but ... comments? I'm not sure that adding a flag to the XML is neccessarily the correct way to do this. The XML is intended to be a description of the VM's virtual hardware / resources. Whether a domain autostarts or not is really administrator defined policy which doesn't match up with intended use of the XML. Similar reason we don't put VCPU pinning information in the XML, because its local machine / administrator defined policy rather than a part of the VM hardware description. I think I'd probably be more inclined to add a formal API for querying whether a domain autostarts, and a second for setting the autostart flag on/off.

The old Xend just stuffs VM configs into a special directory to autostart, so we can detect that by looking for appropriate symlins, and change it by adding/removing the symlinks. The newer Xen 3.0.4 or later has a formal API for setting/querying autostart I believe, but can't remember the details just at the minute.