<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=""><meta http-equiv="Content-Type" content="text/html charset=utf-8" class=""><div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class="">Message: 7<br class="">Date: Thu, 3 Nov 2016 16:50:54 +0000<br class="">From: Jay Faulkner <<a href="mailto:jay@jvf.cc" class="">jay@jvf.cc</a>><br class="">To: "OpenStack Development Mailing List (not for usage questions)"<br class=""><span class="Apple-tab-span" style="white-space: pre;"> </span><<a href="mailto:openstack-dev@lists.openstack.org" class="">openstack-dev@lists.openstack.org</a>><br class="">Subject: Re: [openstack-dev] [nova][ironic] Instance can "migrate" to<br class=""><span class="Apple-tab-span" style="white-space: pre;"> </span>another node?<br class="">Message-ID: <<a href="mailto:1417F96D-BEA5-457A-BA27-96511CBCB422@jvf.cc" class="">1417F96D-BEA5-457A-BA27-96511CBCB422@jvf.cc</a>><br class="">Content-Type: text/plain; charset="utf-8”<div class=""><br class=""></div><div class="">Thanks a lot, this very helpful for me.</div><div class=""><span style="color: rgb(55, 64, 81); font-family: 微软雅黑; font-size: 16px; font-variant-ligatures: normal; orphans: 2; widows: 2;" class="">⌘</span></div><div class=""><br class=""></div><div class=""><blockquote type="cite" class="">Hey, <br class=""><br class="">This is all detailed in the release notes for nova here: <a href="http://docs.openstack.org/releasenotes/nova/newton.html#new-features" class="">http://docs.openstack.org/releasenotes/nova/newton.html#new-features</a> ? just search for ?Ironic?.<br class=""><br class="">Here is the relevant section:<br class="">"Note that instances will still be owned by the same nova-compute service for the entire life of the instance, and so the ironic node that instance is on will also be managed by the same nova-compute service until the node is deleted. This also means that removing a nova-compute service will leave instances managed by that service orphaned, and as such most instance actions will not work until a nova-compute service with the same hostname is brought (back) online.<br class=""><br class="">When nova-compute services are brought up or down, the ring will eventually re-balance (when the resource tracker runs on each compute). This may result in duplicate compute_node entries for ironic nodes while the nova-compute service pool is re-balancing. However, because any nova-compute service running the ironic virt driver can manage any ironic node, if a build request goes to the compute service not currently managing the node the build request is for, it will still succeed.?<br class=""><br class="">So essentially what this means is that for provisioned instances, there?s no way to migrate them off of a failed compute host, but unprovisioned node capacity will rebalance automatically between compute hosts when you provision a new one. Essentially if you have a nova compute host fail but want to be able to continue managing instances deployed by it, you?ll have to build another nova-compute host with the same hostname (or CONF.host setting) in order to do anything beyond deleting it.<br class=""><br class="">Hope this helps,<br class="">Jay Faulkner<br class="">OSIC<br class=""><br class=""><blockquote type="cite" class="">On Nov 3, 2016, at 3:12 AM, c1 <<a href="mailto:c1_dx@yahoo.com" class="">c1_dx@yahoo.com</a>> wrote:<br class=""><br class="">Hi al,<br class=""><br class="">Now, nova?s ironic driver can allow multiple compute services.<br class=""><br class="">I am not sure that, when a compute node is down. <br class=""><br class="">The instances running in it, whether can ?migrate? to another compute node(use ironic driver)?<br class=""><br class=""><br class=""><br class="">Thanks<br class=""><br class="">C1dx <br class=""><br class="">__________________________________________________________________________<br class="">OpenStack Development Mailing List (not for usage questions)<br class="">Unsubscribe: <a href="mailto:OpenStack-dev-request@lists.openstack.org" class="">OpenStack-dev-request@lists.openstack.org</a>?subject:unsubscribe<br class=""><a href="http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev" class="">http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev</a></blockquote></blockquote></div></div></body></html>