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Thank you for the answers.<br>
<br>
I understood the concerns about having the UUID completely user
defined and I also understand Nova has no interest in supporting a
customized algorithm to generate UUID. Anyway I may have found a
solution that will cover my use case and respect the standard for
UUID (RFC 4122 <a class="moz-txt-link-freetext"
href="http://www.ietf.org/rfc/rfc4122.txt">http://www.ietf.org/rfc/rfc4122.txt</a>)
.<br>
<br>
The generation of the UUID in Nova make use of the function <i>uuid4()</i>
from the module <i>uuid.py</i> to have an UUID (pseudo)random,
according to version 4 described in RFC 4122. Anyway this is not the
only algorithm supported in the standard (and implemented yet in <i>uuid.py</i>).<br>
<br>
In particular I focused my attention on UUID version 1 and the
method <i>uuid1(node=None, clock_seq=None)</i> that allows to pass
as parameter a part of the UUID (<i>node</i> is the field containing
the last 12 hexadecimal digits of the UUID). <br>
<br>
So my idea was to give the chance to the user to set uiid version (1
or 4, with the latter as default) when creating a new instance and
in case of version 1 to pass optionally a value for parameter <i>node</i>.<br>
<br>
Any thoughts? <br>
<br>
<div class="moz-cite-prefix">On 09/30/14 14:07, Andrew Laski wrote:<br>
</div>
<blockquote cite="mid:542A9CEA.1010405@rackspace.com" type="cite"> <br>
On 09/30/2014 06:53 AM, Pasquale Porreca wrote: <br>
<blockquote type="cite">Going back to my original question, I
would like to know: <br>
<br>
1) Is it acceptable to have the UUID passed from client side? <br>
</blockquote>
<br>
In my opinion, no. This opens a door to issues we currently don't
need to deal with, and use cases I don't think Nova should
support. Another possibility, which I don't like either, would be
to pass in some data which could influence the generation of the
UUID to satisfy requirements. <br>
<br>
But there was a suggestion to look into addressing your use case
on the QEMU mailing list, which I think would be a better
approach. <br>
<br>
<blockquote type="cite"> <br>
2) What is the correct way to do it? I started to implement this
feature, simply passing it as metadata with key uuid, but I feel
that this feature should have a reserved option rather then use
metadata. <br>
<br>
<br>
On 09/25/14 17:26, Daniel P. Berrange wrote: <br>
<blockquote type="cite">On Thu, Sep 25, 2014 at 05:23:22PM
+0200, Pasquale Porreca wrote: <br>
<blockquote type="cite">This is correct Daniel, except that
that it is done by the virtual <br>
firmware/BIOS of the virtual machine and not by the OS (not
yet installed at <br>
that time). <br>
<br>
This is the reason we thought about UUID: it is yet used by
the iPXE client <br>
to be included in Bootstrap Protocol messages, it is taken
from the <uuid> <br>
field in libvirt template and the <uuid> in libvirt is
set by OpenStack; the <br>
only missing passage is the chance to set the UUID in
OpenStack instead to <br>
have it randomly generated. <br>
<br>
Having another user defined tag in libvirt won't help for
our issue, since <br>
it won't be included in Bootstrap Protocol messages, not
without changes in <br>
the virtual BIOS/firmware (as you stated too) and honestly
my team doesn't <br>
have interest in this (neither the competence). <br>
<br>
I don't think the configdrive or metadata service would help
either: the OS <br>
on the instance is not yet installed at that time (the
target if the network <br>
boot is exactly to install the OS on the instance!), so it
won't be able to <br>
mount it. <br>
</blockquote>
Ok, yes, if we're considering the DHCP client inside the iPXE
BIOS <br>
blob, then I don't see any currently viable options besides
UUID. <br>
There's no mechanism for passing any other data into iPXE that
I <br>
am aware of, though if there is a desire todo that it could be
<br>
raised on the QEMU mailing list for discussion. <br>
<br>
<br>
Regards, <br>
Daniel <br>
</blockquote>
<br>
</blockquote>
<br>
<br>
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href="mailto:OpenStack-dev@lists.openstack.org">OpenStack-dev@lists.openstack.org</a>
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href="http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev">http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev</a>
<br>
</blockquote>
<br>
<pre class="moz-signature" cols="72">--
Pasquale Porreca
DEK Technologies
Via dei Castelli Romani, 22
00040 Pomezia (Roma)
Mobile +39 3394823805
Skype paskporr</pre>
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