> For the complete documentation index, see [llms.txt](https://platform9.com/kb/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://platform9.com/kb/pmo/how-to/vm-migration-fails-with-error-unable-to-create-allocation-for.md).

# VM migration fails with error 'Unable to create allocation for 'DISK\_GB' on resource provider'

## Problem

* Migration of a VM instance fails with below error:

{% tabs %}
{% tab title="Javascript" %}

```javascript
2022-10-04 10:52:32.471 5924 WARNING nova.scheduler.client.report [req-150eabb9-xxxx-xxxx-994d-b80a5787ab35 b8935406ffda4a6ab1316777dbda1bba a317fe3586ed474e9605c3464487be97 - default default] Unable to post allocations for consumer 369f7d20-0e97-49a1-9b93-ea2325803ddf (409 {"errors": [{"status": 409, "title": "Conflict", "detail": "There was a conflict when trying to complete your request.<br> Unable to allocate inventory: Unable to create allocation for 'DISK_GB' on resource provider 'f9c9c94e-xxxx-xxxx-96bb-c8257362f2a5'. The requested amount would exceed the capacity.  ", "code": "placement.undefined_code", "request_id": "req-b1a81585-e977-4b34-aa17-78c8e7fff49b"}]})
```

{% endtab %}
{% endtabs %}

## Environment

* Platform9 Managed OpenStack - v5.4.0 and Higher

Cause

* The disk space was overcommitted on the source host and nova-scheduler does care about the disk space being over-committed on the source.

## Resolution

* Edit the /opt/pf9/etc/nova/conf.d/nova\_override.conf file on the source host.
* Increase "disk\_\_\_allocation\_\_\_ratio" (to a value something like 1.5).
* Restart pf9-ostackhost service:

{% tabs %}
{% tab title="Javascript" %}

```javascript
# systemctl restart pf9-ostackhost
# systemctl status pf9-ostackhost
```

{% endtab %}
{% endtabs %}

## Additional Information

* <https://bugzilla.redhat.com/show_bug.cgi?id=1711348>


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