# Troubleshooting

Use the items below to identify common Collector issues, understand likely causes, and apply the recommended resolution.

## Installation

## Collector fails immediately after starting

Check the service log:

```
sudo journalctl -u pho-collector -n 100 --no-pager
```

Run the collector interactively to expose configuration errors:

```
sudo -u pho-collector \
  /opt/particle_horizon/pho-collector \
  --config=/opt/particle_horizon/local_config/pho-collector/config.yaml
```

## Permission denied errors

Verify that the service account can access the installation:

```
sudo -u pho-collector \
  test -x /opt/particle_horizon/pho-collector
```

Check runtime-directory ownership:

```
ls -ld \
  /opt/particle_horizon/local_data/pho-collector \
  /opt/particle_horizon/logs/pho-collector
```

These directories should normally be writable by `pho-collector`.

## Confirm which release is installed

Inspect the stable symlink:

```
readlink -f /opt/particle_horizon/pho-collector
```

Build metadata for each installed version is available beneath:

```
/opt/particle_horizon/SOFTWARE/pho-collector-<version>-linux-<arch>/BUILD_INFO.txt
```

For example:

```
cat /opt/particle_horizon/SOFTWARE/pho-collector-*/BUILD_INFO.txt
```