I'm trying to deploy TripleO OverCloud .. and i'm stuck with this step :


My idea is :

  • Currently i've one Hypervisor server KVM
  • I created a Guest node for UnderCloud on same host
  • I created a Guest node for BlockStorage
  • I installed VirtualBMC on these nodes in order to simulate IPMI control
  • The blocker now is with Compute node where as per my understanding it should be a physical hypervisor server . so my Idea is to use the Host hypervisor itself as a Compute note thus it will be possible to create instances through.. but my problem is :

How can i define it inside instackenv.json in order to describe the node ? so mu though is i will need to install a simulation like VirtualMBC but for the host itself not for the virtual .. Thus OpenStack would be able of managing the hypervisor node and creating the VMs.

Correct me please and your help

  • There are some third party guides out there about doing TripleO on a single host. I would suggest finding one, as this setup that you have linked expects three different bare metal servers. – Michael Hampton Feb 8 '18 at 21:57
  • @MichaelHampton yes i saw TripeO quick start .. but is that a good decision to do that on a small production environment .. where i alway read this phrase in every document "Use that scenario in case of testing / development" so i though it's not recommended for production use ? – Jason4Ever Feb 8 '18 at 22:12
  • Using one server alone is never recommended for production use! – Michael Hampton Feb 8 '18 at 22:14
  • @MichaelHampton yes i'm totally agree with you . now i understood this point . i think there is no problem if i'll use it for understanding the technology + for creating 4 or 5 VM instances for personal use .. i though before that required meant for this warning was related to the security and issues in general even with the small use . i guess that was a misunderstanding from me .. correct me if i'm mistaken .. appreciate – Jason4Ever Feb 8 '18 at 22:21
  • It's not recommended for production because it's a single point of failure. If you have only one compute node, for instance, you cannot live migrate VMs to another node in order to perform maintenance. If the node goes down for any other reason, you have no other node on which to run your VMs while you repair it. If you can live with all of this, then a single node is fine. – Michael Hampton Feb 8 '18 at 22:29

It's already been said this is not for production.

As for your idea for the hypervisor to serve as compute, I'm afraid that will not be possible (without some very hacky workarounds at least). The problem is, ironic in the undercloud needs to powercycle all the overcloud nodes to set them to boot from PXE and install them. If the hypervisor running the undercloud VM is powercycled by the undercloud VM, you're going to find yourself without a setup.

In test environments, what I usually do is create additional VMs to serve as compute nodes, with nested virtualization enabled. Again, not for production, but good enough to test things out. This is in fact the reason vbmc was created - to manage such setups using IPMI instead of the old pxe_ssh driver.

There are some nicely automated ways of building such a setup, I've been using infrared[1] with a lot of success

[1] http://infrared.readthedocs.io/en/latest/


During a TripleO installation every node in the undercloud has a defined role: Director, Compute, Storage, Network, ... If I understood your question correctly, you want to know if it is possible to run the Director node as compute node as well? I am afraid the answer to that question is no, each node in a Undercloud can only have one and only one role assigned.

  • Could you provide some detail giving support to your reply? – Dave M May 4 '18 at 18:36
  • I hope this helps. – José Castillo Lema May 4 '18 at 19:38

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