[Openstack-operators] Nova hypervisor uuid

Matt Riedemann mriedemos at gmail.com
Tue Nov 27 18:02:25 UTC 2018

On 11/27/2018 11:32 AM, Ignazio Cassano wrote:
> Hi  All,
> Please anyone know where hypervisor uuid is retrived?
> Sometime updating kmv nodes with yum update it changes and in nova 
> database 2 uuids are assigned to the same node.
> regards
> Ignazio
> _______________________________________________
> OpenStack-operators mailing list
> OpenStack-operators at lists.openstack.org
> http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-operators

To be clear, do you mean the computes_nodes.uuid column value in the 
cell database? Which is also used for the GET /os-hypervisors response 
'id' value if using microversion >= 2.53. If so, that is generated 
randomly* when the compute_nodes table record is created:



When you hit this problem, are you sure the hostname on the compute host 
is not changing? Because when nova-compute starts up, it should look for 
the existing compute node record by host name and node name, which for 
the libvirt driver should be the same. That lookup code is here:


So the only way nova-compute should create a new compute_nodes table 
record for the same host is if the host/node name changes during the 
upgrade. Is the deleted value in the database the same (0) for both of 
those records?

* The exception to this is for the ironic driver which re-uses the 
ironic node uuid as of this change: https://review.openstack.org/#/c/571535/




More information about the OpenStack-operators mailing list