<html><head><meta http-equiv="Content-Type" content="text/html charset=utf-8"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class="">Hi Florian,<div class=""><br class=""></div><div class="">It is possible, though maybe not for the faint of heart depending on your strategy. You can:</div><div class=""><br class=""></div><div class="">1. Create new VLAN networks using the same subnet CIDRs as the existing GRE networks, then detach existing interfaces and attach new interfaces with the same IPs. You would need to detach/attach router interfaces as well and maybe change floating IP associations. There are quite a few steps here but it is possible.</div><div class=""><br class=""></div><div class="">2. Make the changes to the database and restart services. This is not the route I would go if I could avoid it, but it has been done. We went from OVS/GRE to ML2/LinuxBridge/VLAN over a year ago in some live environments. I highly recommend simulating this in a lab environment before doing it live. </div><div class=""><br class=""></div><div class="">Here’s some links on the latter that talk about what we did:</div><div class=""><br class=""></div><div class=""><a href="https://www.openstack.org/summit/openstack-paris-summit-2014/session-videos/presentation/migrating-production-workloads-from-ovs-to-linux-bridge-w-ml2" class="">https://www.openstack.org/summit/openstack-paris-summit-2014/session-videos/presentation/migrating-production-workloads-from-ovs-to-linux-bridge-w-ml2</a></div><div class=""><br class=""></div><div class=""><a href="https://github.com/busterswt/openstackparis2014" class="">https://github.com/busterswt/openstackparis2014</a></div><div class=""><br class=""></div><div class=""><div apple-content-edited="true" class="">
<div class=""><div class="">James </div></div>
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<br class=""><div><blockquote type="cite" class=""><div class="">On Oct 18, 2015, at 3:15 AM, Florian Rommel <<a href="mailto:florian.rommel@datalounges.com" class="">florian.rommel@datalounges.com</a>> wrote:</div><br class="Apple-interchange-newline"><div class=""><div class="">Hi, I have a problem that I need to convert our Dev environment to VLAN from GRE tunnels.<br class="">Can someone assist me on how complicated it is? the environment is about 10 nodes including compute, storage and control nodes.<br class=""><br class="">There can be a LITTLE bit of downtime but not that much (hour, maybe 2?)<br class="">Is this even possible?<br class=""><br class=""><br class="">Thanks for any help, you can also contact me directly.<br class=""><br class="">Best regards,<br class="">//Florian<br class="">_______________________________________________<br class="">Mailing list: <a href="http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack" class="">http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack</a><br class="">Post to : <a href="mailto:openstack@lists.openstack.org" class="">openstack@lists.openstack.org</a><br class="">Unsubscribe : <a href="http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack" class="">http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack</a><br class=""></div></div></blockquote></div><br class=""></div></body></html>