Can't create guest with more than 240 VCPUs

Solution In Progress - Updated -


  • Appreciate this may be somewhere in the documentation, but are the numbers of CPUs and amount of RAM reserved for the hypervisor auto-generated based on node's capacity, or are they values we can tune?

  • I have a 128 core (with SMT enabled) hypervisor and I can't seem to deploy a virtual flavour with more than about 240 CPUs. 16 (or 8 physical) seems a lot to be reserving for the hypervisor, and it also seems to be reserving a large amount of 1TB RAM.

  • Can we adjust that? We are not looking to overcommit CPUs on these nodes, just deploy a single huge VM with as many resources as possible.


  • Red Hat OpenStack Platform 16.2 (RHOSP)

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