Unable to Create Virtual Machine on Compute Host – Host Not Mapped to Any Cell

Problem

Virtual Machine creation fails with the following error:

VM Creation Logs
Copy

Environment

  • Self-Hosted Private Cloud Director Virtualization - v2025.4 and Higher
  • Self-Hosted Private Cloud Director Kubernetes - v2025.4 and Higher

For Private Cloud Director (SaaS) users, if you encounter the same issue, please contact Platform9 Support.

Cause

The compute host was not properly mapped to any Nova cell. This can happen if:

  • The host was added without triggering automatic cell discovery.
  • The host was removed or modified in a way that removed its mapping from the cell database.

Without this mapping, Nova is unable to schedule workloads on the host, even if it appears active and functional.

Diagnostics

  1. Run the following command from the nova-scheduler pod on Management Plane to see if the host is linked to a cell:
nova-manage command
Copy
  1. The compute service on the host still might be visible and enabled:
Openstack Command
Copy

Resolution

  1. Run the following command from nova-scheduler pod on Management Plane to find any unmapped compute hosts and create their cell mappings:
nova-manage command
Copy

Validation

  1. Confirm the host is mapped to a cell.
nova-manage command
Copy
  1. Verify the compute service is active
Openstack Command
Copy
  1. Attempt to launch a virtual machine and confirm it succeeds.
Type to search, ESC to discard
Type to search, ESC to discard
Type to search, ESC to discard