# Using DEB

The Debian package for Snow Owl can be downloaded from the Downloads section. It can be used to install Snow Owl on any Debian-based system such as Debian and Ubuntu.

## Download and install

```bash
wget https://github.com/b2ihealthcare/snow-owl/releases/download/<version>/snow-owl-oss-<version>.deb
wget https://github.com/b2ihealthcare/snow-owl/releases/download/<version>/snow-owl-oss-<version>.deb.sha512
shasum -a 512 -c snow-owl-oss-<version>.deb.sha512 # Compares the SHA of the downloaded Debian package and the published checksum, which should output `snow-owl-oss-<version>.deb: OK`.
sudo dpkg -i snow-owl-oss-<version>.deb
```

## Running Snow Owl with SysV init

Use the update-rc.d command to configure Snow Owl to start automatically when the system boots up:

```bash
sudo update-rc.d snowowl defaults 95 10
```

Snow Owl can be started and stopped using the service command:

```bash
sudo -i service snowowl start
sudo -i service snowowl stop
```

If Snow Owl fails to start for any reason, it will print the reason for failure to STDOUT. Log files can be found in `/var/log/snowowl/`.

## Running Snow Owl with systemd

To configure Snow Owl to start automatically when the system boots up, run the following commands:

```bash
sudo /bin/systemctl daemon-reload
sudo /bin/systemctl enable snowowl.service
```

Snow Owl can be started and stopped as follows:

```bash
sudo systemctl start snowowl.service
sudo systemctl stop snowowl.service
```

These commands provide no feedback as to whether Snow Owl was started successfully or not. Instead, this information will be written in the log files located in `/var/log/snowowl/`.

## Checking that Snow Owl is running

You can test that your Snow Owl instance is running by sending an HTTP request to:

```bash
curl http://localhost:8080/snowowl/info
```

which should give you a response something like this:

```json
{
  "version": "<version_number>",
  "description": "You Know, for Terminologies",
  "repositories": {
    "items": [
      {
        "id": "snomedStore",
        "health": "GREEN"
      }
    ]
  }
}
```

## Configuring Snow Owl

Snow Owl defaults to using `/etc/snowowl` for runtime configuration. The ownership of this directory and all files in this directory are set to `root:snowowl` on package installation and the directory has the `setgid` flag set so that any files and subdirectories created under `/etc/snowowl` are created with this ownership as well (e.g., if a keystore is created using the keystore tool). It is expected that this be maintained so that the Snow Owl process can read the files under this directory via the group permissions.

Snow Owl loads its configuration from the `/etc/snowowl/snowowl.yml` file by default. The format of this config file is explained in [Configuring Snow Owl](https://docs.b2ihealthcare.com/snow-owl/setup-and-administration/advanced-configuration).

{% hint style="info" %}
NOTE: Distributions that use `systemd` require that system resource limits be configured via `systemd` rather than via the `/etc/sysconfig/snowowl` file.
{% endhint %}

## Directory layout of Debian package

The Debian package places config files, logs, and the data directory in the appropriate locations for a Debian-based system:

| Type | Description                                                          | Default Location         | Setting                                                                                                |
| ---- | -------------------------------------------------------------------- | ------------------------ | ------------------------------------------------------------------------------------------------------ |
| home | Snow Owl home directory or `$SO_HOME`                                | `/usr/share/snowowl`     |                                                                                                        |
| bin  | Binary scripts including startup/shutdown to start/stop the instance | `/usr/share/snowowl/bin` |                                                                                                        |
| conf | Configuration files including `snowowl.yml`                          | `/etc/snowowl`           | [SO\_PATH\_CONF](https://docs.b2ihealthcare.com/snow-owl/advanced-configuration#config-files-location) |
| data | The location of the data files and resources.                        | /var/lib/snowowl         | path.data                                                                                              |
| logs | Log files location.                                                  | /var/log/snowowl         |                                                                                                        |