On a compute node, if you destroy an instance, the instance cache may remain on disk. The manner by which you destroy the instance does not matter. It could be by using the nova delete command, or by using the kollacli host destroy command to destroy the services on the compute node. The instance cache may remain on disk in the /var/lib/kolla/var/lib/nova/instances/_base/ directory on the node.

Workaround: If no instances are running on the node, you can safely remove the instance cache files manually. To check if any instances are running on the compute node, enter the following from the master node:

$ nova list --host compute_hostname --all-tenants
+----+------+-----------+--------+------------+-------------+----------+
| ID | Name | Tenant ID | Status | Task State | Power State | Networks |
+----+------+-----------+--------+------------+-------------+----------+
+----+------+-----------+--------+------------+-------------+----------+

If no instances are running, enter the following on the compute node:

# rm -rf /var/lib/kolla/var/lib/nova/instances/_base/ 

Bug: 22887481