> 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/solution/unable-to-start-pf9-ostackhost-service.md).

# Unable to Start pf9-ostackhost Service

## Problem

* Unable to start ***pf9-ostackhost*** service on a KVM host.
* Below messages are seen in */var/log/pf9/ostackhost.log **.***

{% tabs %}
{% tab title="None" %}

```none
950 INFO nova.service [-] Starting compute node (version 2013.2.0)800 ERROR oslo_service.service [-] Error starting thread.: InternalError: Nova requires QEMU version 2.0.0 or greater.800 TRACE oslo_service.service Traceback (most recent call last):800 TRACE oslo_service.service  File "/opt/pf9/venv/lib/python2.7/site-packages/oslo_service/service.py", line 796, in run_service800 TRACE oslo_service.service    service.start()800 TRACE oslo_service.service  File "/opt/pf9/venv/lib/python2.7/site-packages/nova/service.py", line 162, in start800 TRACE oslo_service.service    self.manager.init_host()800 TRACE oslo_service.service  File "/opt/pf9/venv/lib/python2.7/site-packages/nova/compute/manager.py", line 1208, in init_host800 TRACE oslo_service.service    self.driver.init_host(host=self.host)800 TRACE oslo_service.service  File "/opt/pf9/venv/lib/python2.7/site-packages/nova/virt/libvirt/driver.py", line 540, in init_host800 TRACE oslo_service.service    libvirt_utils.version_to_string(PF9_MIN_QEMU_VERSION))800 TRACE oslo_service.service InternalError: Nova requires QEMU version 2.0.0 or greater.
```

{% endtab %}
{% endtabs %}

## Environment

* Platform9 Managed OpenStack - v4.0
* Red Hat Enterprise Linux Server - v7.4

## Cause

* The minimum version of QEMU should be 2.0 or greater but on the KVM host the version is 1.5.3.
* Use below command to check the QEMU version.

{% tabs %}
{% tab title="None" %}

```none
$ /usr/libexec/qemu-kvm --versionQEMU emulator version 1.5.3 (qemu-kvm-1.5.3-160.el7_6.1), Copyright (c) 2003-2008 Fabrice Bellard
```

{% endtab %}
{% endtabs %}

## Resolution

1. Upgrade QEMU package to 2.0 or higher.

## Additional Information

QEMU version can be checked using **`virsh`** command.

{% tabs %}
{% tab title="None" %}

```none
virsh # versionCompiled against library: libvirt 4.5.0Using library: libvirt 4.5.0Using API: QEMU 4.5.0Running hypervisor: QEMU 1.5.3
```

{% endtab %}
{% endtabs %}


---

# Agent Instructions
This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com.

## Querying This Documentation
If you need additional information that is not directly available in this page, you can query the documentation by asking a question.

Perform an HTTP GET request on the following URL with the `ask` and `goal` query parameters:

```
GET https://platform9.com/kb/pmo/solution/unable-to-start-pf9-ostackhost-service.md?ask=<question>&goal=<user_goal>
```

`ask` is the immediate question: it should be specific, self-contained, and written in natural language.
`goal` is what the user is ultimately trying to achieve, the reason they need the answer. Sharing it helps GitBook give you a better, more relevant answer. A goal is most helpful when it describes the outcome the user wants rather than restating the question. For example, with `ask=how do I create an API token`, a goal like `automate deployments from our CI pipeline` lets GitBook tailor the answer to that use case.

The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.