# Deploy a floating license server

```{note}
This page only applies to **commercial use** of ACEMD. Non-commercial use is free and does not require a license file or server — see [License options](../explanation/license-options.md).
```

**You will learn:** how to stand up the Acellera floating-license server for an HPC cluster and point ACEMD clients at it.

**Prerequisites:**

- A floating-license `license.dat` file from Acellera, bound to the **MAC address** of the host that will run the server.
- A host accessible to your cluster: CentOS 7 or compatible, fixed MAC address, root access.

For the comparison between license types (when a floating license is the right choice), see [License options](../explanation/license-options.md).

## Step 1 — Download the server

On the host that will run the license server:

```bash
curl -s https://software.acellera.com/floating-licence-server.tar.gz | tar xzvf -
```

## Step 2 — Install (as root)

```bash
cd floating-licence-server
sudo ./install.sh
```

By default the server is installed under `/opt/acellera` and runs as the `sglmd` user. Override either with `ROOT=` and `USER=` environment variables before invoking `install.sh`.

## Step 3 — Place the license file

```bash
sudo cp license.dat /opt/acellera/license.dat
sudo chown sglmd:sglmd /opt/acellera/license.dat
sudo chmod 644 /opt/acellera/license.dat
```

Confirm that `sglmd` can read the file.

## Step 4 — Start the server

```bash
sudo service acellera.sglmd start
```

Check the log to confirm it started cleanly:

```bash
tail /var/log/acellera.sglmd.log
```

Healthy output looks like:

```text
2020/01/01 00:00:00 Server starting on localhost, port 27000, max components 64, max connections 256
Enabling acemd 3.0 512 01-jan-2025
Ready...
```

This server is accepting up to 512 concurrent ACEMD licenses on port `27000`, expiring `2025-01-01`.

## Step 5 — Open the firewall

The server listens on TCP port `27000` by default. Clients must be able to reach this port over the network. Adjust your firewall accordingly.

## Step 6 — Point ACEMD clients at the server

On each client machine, set `ACELLERA_LICENSE_SERVER` to `<port>@<host>`:

```bash
export ACELLERA_LICENSE_SERVER=27000@license.internal.acellera.com
```

Verify:

```bash
acemd --license
```

A working setup reports the floating-license check as `GRANTED`. If it doesn't, the client cannot reach the server — verify network connectivity to the host on the configured port.

## Gotchas

- The license file's MAC binding is to the **server's** MAC, not the clients'. Clients only need network access to the server.
- The historical British-spelling env var `ACELLERA_LICENCE_SERVER` still works for backward compatibility; new installs should use `ACELLERA_LICENSE_SERVER`.

## See also

- [License options](../explanation/license-options.md)
- [Install a node-locked license](install-a-node-locked-license.md)