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<p class="MsoNormal"><span style="font-size:11.0pt">Hi Christian,<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt">I documented this a few months ago here:
<a href="https://www.jimmdenton.com/migrating-lxb-to-ovn/">https://www.jimmdenton.com/migrating-lxb-to-ovn/</a>. It’s heavily geared towards OpenStack-Ansible, but you can probably extrapolate the steps for a vanilla deployment or other deployment tool. The
details will vary. Highly recommend testing this in a lab environment that mirrors production, if possible.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt"><o:p> </o:p></span></p>
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<p class="MsoNormal"><span style="font-size:11.0pt">-- <o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:11.0pt">James Denton<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt">Principal Architect<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt">Rackspace Private Cloud - OpenStack<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:11.0pt">james.denton@rackspace.com</span><span style="font-size:11.0pt"><o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt"><o:p> </o:p></span></p>
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<p class="MsoNormal" style="margin-bottom:12.0pt"><b><span style="font-size:12.0pt;color:black">From:
</span></b><span style="font-size:12.0pt;color:black">Christian Rohmann <christian.rohmann@inovex.de><br>
<b>Date: </b>Wednesday, November 23, 2022 at 4:27 AM<br>
<b>To: </b>James Denton <james.denton@rackspace.com>, Slawek Kaplonski <skaplons@redhat.com>, openstack-discuss@lists.openstack.org <openstack-discuss@lists.openstack.org><br>
<b>Subject: </b>Re: [neutron] Switching the ML2 driver in-place from linuxbridge to OVN for an existing Cloud<o:p></o:p></span></p>
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<p class="MsoNormal" style="line-height:12.0pt;background:#FFEB9C"><b><span style="color:#9C6500">CAUTION:</span></b><span style="color:black"> This message originated externally, please use caution when clicking on links or opening attachments!<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:11.0pt"><o:p> </o:p></span></p>
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<p class="MsoNormal"><span style="font-size:11.0pt">Hey James,<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:11.0pt"><o:p> </o:p></span></p>
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<p class="MsoNormal"><span style="font-size:11.0pt">I am really sorry I just get back to you now.<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:11.0pt"><o:p> </o:p></span></p>
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<p class="MsoNormal"><span style="font-size:11.0pt">On 29/08/2022 19:54, James Denton wrote:<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:11.0pt"> </span><o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:11.0pt">In my experience, it is possible to perform in-place migration from ML2/LXB -> ML2/OVN, albeit with a shutdown or hard reboot of the instance(s) to complete the VIF plugging and some other needed operations.
I have a very rough outline of required steps if you’re interested, but they’re geared towards an openstack-ansible based deployment. I’ll try to put a writeup together in the next week or two demonstrating the process in a multi-node environment; the only
one I have done recently was an all-in-one.</span><o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:11.0pt"> </span><o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:11.0pt">James Denton</span><o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:11.0pt">Rackspace Private Cloud</span><o:p></o:p></p>
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<p><o:p> </o:p></p>
<p>Thanks for replying, I'd really love to see your outline / list of steps. BTW, we are actively working on switching to openstack-ansible - so that would suit us well.<br>
We also came to the conclusion that a shutdown of all instances might be required. Question is, if that has to happen instantly or if one could do that on a project by project base.<br>
Our cloud is small enough to still make this feasible, but I suppose this topic is or will become more important to other, larger clouds as well.<o:p></o:p></p>
<p><o:p> </o:p></p>
<p>Regards<o:p></o:p></p>
<p><o:p> </o:p></p>
<p>Christian<o:p></o:p></p>
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