# Troubleshooting offline or failed hosts

When you see a hypervisor host in a <code class="expression">space.vars.product\_name</code> environment that's **offline, failed, or in an error state**, here's how to debug the issue:

## Most common causes

* Connectivity to the <code class="expression">space.vars.product\_name</code> management plane controller is broken or unreachable.
* Dependent services are down.
* Packages are corrupted or not installed.
* NTP is not synchronized.
* Insufficient disk space available.
* Ensure that the host you are trying to add meets the [pre-requisites](https://platform9.com/docs/private-cloud-director/private-cloud-director/pre-requisites#host-hardware-and-configuration).

## Steps To Troubleshoot

{% stepper %}
{% step %}

### Verify outbound network connectivity

Ensure the host can reach the internet and the <code class="expression">space.vars.product\_name</code> management plane controller:

```bash
$ curl -s https://<FQDN>
$ ping www.google.com
$ telnet www.google.com 443
```

{% endstep %}

{% step %}

### Proxy configuration (if applicable)

If your environment uses a proxy, configure the Platform9 host agent on the host to route traffic via the proxy:

```bash
$ sudo bash <path to host agent installer> --proxy=<proxy server>:<proxy port>
```

{% endstep %}

{% step %}

### Verify hostname consistency

Make sure the hostname on the host matches the hostname shown in the GUI.
{% endstep %}

{% step %}

### Verify host UUID

Confirm the UUID in the `host_id` file matches the host UUID shown in the GUI:

```bash
$ sudo cat /etc/pf9/host_id.conf
```

{% endstep %}

{% step %}

### Verify NTP configuration

If NTP is enabled, ensure NTP servers are configured correctly across nodes in:

```
/etc/systemd/timesyncd.conf.d/conf.d
```

{% endstep %}

{% step %}

### Verify Platform9 packages

Check that Platform9 packages are installed and match the version shown in the <code class="expression">space.vars.product\_name</code> GUI:

```bash
$ sudo apt list | grep -i pf9*
```

{% endstep %}

{% step %}

### Confirm host agent services are running

Check the status of the Platform9 services:

```bash
$ sudo service pf9-hostagent status
$ sudo service pf9-ostackhost status
$ sudo service pf9-comms status
$ sudo service pf9-sidekick status
```

{% endstep %}

{% step %}

### Inspect service logs

Check logs for errors, timeouts, or warnings around the time of the issue and verify whether recent network changes could have impacted connectivity:

```bash
$ sudo cat /var/log/pf9/hostagent.log
$ sudo cat /var/log/pf9/ostackhost.log
$ sudo cat /var/log/pf9/comms/comms.log
$ sudo cat /var/log/pf9/sidekick/sidekick.log
```

{% endstep %}

{% step %}

### Contact Platform9 Support

If these steps don't resolve the issue, reach out to the [Platform9 Support team](https://support.platform9.com/) for additional assistance.
{% endstep %}
{% endstepper %}