[Libvir] [RFC] Life-cycle Management of the domain take2

Saori Fukuta fukuta.saori at jp.fujitsu.com
Wed May 16 06:28:14 UTC 2007


Thank you for your comment.

On Fri, 11 May 2007 19:29:48 +0100 "Daniel P. Berrange" wrote:
> On Fri, May 11, 2007 at 07:15:33PM +0100, Daniel P. Berrange wrote:
> > 
> > If the guest was created by libvirt, then I consider it a bug if the XML
> > dump does not allow re-creation in exact same config. 
> > 
> > If the guest was created by non-libvirt app, then there may be some xen 
> > specific bits we don't support in libvirt. So be it - there are some things
> > we simply don't want to support. For any of the latter  case, we can at 
> > least evaluate whether it makes sense to support them throughout libvirt,
> > and/or accept patches.

That means the libvirt basically supports a guest that was created by libvirt
( or virt-install ), right ?
I think that would be a waste because we would miss an opportunity to get 
new customers. I personally want to support the guest was created by non-libvirt
app too.

> > The main flaw I see currently is that the vncpassword is missing from the
> > XML. We left that out for security obviously. We definitely have to exclude
> > it if using a read-only connection. For a read-write connection we should
> > probably continue to exclude it by default, since apps often write the XML
> > dump to logfiles. We do fortunately have a (currently unused) flags argument
> > to virDomainGetXMLDesc
> > 
> >   char *                  virDomainGetXMLDesc     (virDomainPtr domain,
> >                                                    int flags);
> > 
> > I propose we add a flag LIBVIRT_XML_INCLUDE_SENSITIVE  or something like
> > that. If that flag were used, then we could include the password in the
> > returned XML. Any apps using that flag would be aware that the XML should
> > be treated as sensitive & thus not logged.
> On this subject of XML dumps for live VMs, there is the option that the
> live VM config will be different from the one on disk. Currently the
> virDomainGetXMLDesc will always give you the live config if the guest
> is running, and the disk config if the guest is not running. The option
> missing here is obviously a way to get the disk config if the guest is
> running. Now we have this convenient flags arg here still which we could
> use:
>   char *livexml = virDomainGetXMLDesc(dom, 0);
>   char *diskxml = virDomainGetXMLDesc(dom, VIR_DOMAIN_XML_INACTIVE);
> Once you have the real diskxml, then you can update it & use the 
>   virDomainDefineXML(dom, diskxml)
> to re-write it on disk,
>   virDomainCreate(dom, diskxml)
> if you want to create a VM with the new config, without actually updating
> the config on disk

It is good idea to use that flags. I would like to use your idea when the fix of
domainDumpXML is needed.
But I am afraid that I am not in a position to go further, because I have not
had a discussion about this RFC still enough.
This is a important things, so I keep your idea in my mind !

Saori Fukuta

More information about the libvir-list mailing list