Description of problem:

It's not possible to resize an existing instance using different page sizes for the new flavor.

Version-Release number of selected component (if applicable):


How reproducible:
100%


Steps to Reproduce:
1. Create an instance with 2M hugepage size by setting flavor property: hw:mem_page_size=2048
2. Make sure every other compute node is configured with 1G huge pages
3. Create a new flavor with the property: hw:mem_page_size=1048576
4. Resize the instance as " openstack server resize --flavor <new flavor UUID> <instance UUID>"
5. 

Actual results:

Resize will fail wit the error message: "Host does not support requested memory pagesize. Requested: 2048 kB _numa_fit_instance_cell /usr/lib/python2.7/site-packages/nova/virt/hardware.py:936"

Expected results:

Resize operation rebuilds the instance just like cold-migration. It should be able to apply all aspects of the new flavor.

Additional info:

Flavor details:

| 802  | <flavor name>         | 12288 |   20 |         0 |     6 | True      |      |         1.0 | aggregate_instance_extra_specs:pinned='true', hw:cpu_policy='dedicated', hw:cpu_thread_policy='require', hw:mem_page_size='1048576'


$ openstack server resize --flavor 802 <instance UUID> --wait; openstack server resize --confirm <instance UUID>
No valid host was found. No valid host found for resize (HTTP 400) (Request-ID: req-568391e8-9efc-485f-a9cc-71798c62b9d2)

Nova scheduler log:

DEBUG nova.virt.hardware [req-568391e8-9efc-485f-a9cc-71798c62b9d2 ...] Host does not support requested memory pagesize. Requested: 2048 kB _numa_fit_instance_cell /usr/lib/python2.7/site-packages/nova/virt/hardware.py:936