[Libvir] [RFC]OpenVZ XML def

[Daniel Veillard]

On Tue, Mar 13, 2007 at 10:57:23PM +0530, Shuveb Hussain wrote:
> Hi,

  Hi,

> I am adding OpenVZ support to Libvirt and work is progressing well.

 Excellent news !

> I'm able to list VM instances and I'm slowly trying to cover the basic
> API functions one by one. That brings  us to the creation of OpenVZ
> based VMs. Just wanted to discuss the basic XML definition format so
> that I can get comments and improve if need be:
> 
> <domain type='openvz'>
>  <name>openvzdemo</name>
>  <uuid>55a2441d-e012-40fe-a4f7-78e176015d40</uuid>
>  <vpsid>101</vpsid>
>  <profile>vps.basic</profile>

  as fixed in second mail

>  <onboot>true</onboot>
>  <os template='slackware-10.2-i386-minimal'/>
>  <network>
>      <hostname>openvzhost</hostname>
>      <ip address='192.168.1.101'
>          netmask='255.255.255.0'
>          defgw='192.168.1.1'
>      />
>      <nameserver>192.168.1.1</nameserver>
>      <nameserver>202.56.250.5</nameserver>
>  </network>
> </domain>
> 
> Does this look OK?

  In general I expect we will need to do some exchanges over the format,
first to try to get as much as possible something similar to the existing
XML instances for the other engines like Xen and QEmu, and second to understand
the ways in which OpenVZ is sufficiently different that it requires a change
in markup.

  There are things a bit surprising:
    - vpsid: I assume it's an identifier for that domain, not as permanent
      as the UUID but which should be sufficient to designate a running
      domain, right ? If yes make it an id attribute in the top element 
      domain as in the example at http://libvirt.org/format.html
    - profile: what is this ? shouldn't the associated informations 
      actually be in the XML and not in some kind of config files (libvirt
      is being extended to be network aware, referencing a remote description
      would be a problem)
    - os: that's probably one place where OpenVZ may be quite different from 
      Xen and QEmu, still what does the string 'slackware-10.2-i386-minimal'
      mean ? Is that a pointer to a file ? If yes shouldn't the associated
      content be in the XML instead

  For the networking <network> looks more like what Mark did in the last week,
I would rather keep the same interfaces, however I'm suprized that you're
not listing any device in the format, not even one for the network interface.

  So as-is the format is really too different from what I would expect, 
also the XML must be sufficient to fully describe a domain instance, so 
this will probably require some discussion to find out what is really needed
in it :-)

Daniel


-- 
Red Hat Virtualization group http://redhat.com/virtualization/
Daniel Veillard      | virtualization library  http://libvirt.org/
veillard at redhat.com  | libxml GNOME XML XSLT toolkit  http://xmlsoft.org/
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