# CUDA Compatibility Drivers

{% hint style="warning" %}
This procedure is considered experimental.
{% endhint %}

In some situations, you might not be able to upgrade NVIDIA CUDA drivers on a regular basis. To work around this issue, NVIDIA provides compatibility drivers that allow users to use newer features without requiring a full upgrade. For information about compatibility drivers, see <https://docs.nvidia.com/deploy/cuda-compatibility/index.html>.

## Installing the Drivers

Use the following commands to install the CUDA 11 compatibility drivers on Ubuntu:

```bash
wget 
https://developer.download.nvidia.com/compute/cuda/repos/ubuntu2004/x86_64/cuda-ubuntu2004.pin

mv cuda-ubuntu2004.pin /etc/apt/preferences.d/cuda-repository-pin-600 

apt-key adv --fetch-keys 
https://developer.download.nvidia.com/compute/cuda/repos/ubuntu2004/x86_64/7fa2af80.pub

add-apt-repository "deb 
https://developer.download.nvidia.com/compute/cuda/repos/ubuntu2004/x86_64/ /" 

apt update 

nvidia-smi 

apt install cuda-compat-11-0 

nvidia-smi 

export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/usr/local/cuda-11.0/compat/ 

nvidia-smi
```

After the last `nvidia-smi`, ensure that CUDA shows the correct version.

{% hint style="info" %}
The driver version will still show as the old version.
{% endhint %}

## Updating systemd Files

After installing the drivers, update the systemd files in /lib/systemd/system/heavydb.service.

In the service section, add or update the environment property

```bash
Environment=LD_LIBRARY_PATH=/usr/local/cuda-11.0/compat:$LD_LIBRARY_PATHbash
```

The file should look like that

```bash
[Unit] 
Description=HEAVY.AI database server 
After=network.target remote-fs.target

[Service] 
Environment=LD_LIBRARY_PATH=/usr/local/cuda-11.0/compat:$LD_LIBRARY_PATH
User=heavyai 
Group=heavyai 
WorkingDirectory=/opt/heavyai
ExecStart=/opt/heavyai/bin/heavydb --config /var/lib/heavyai/heavy.conf 
KillMode=control-group 
SuccessExitStatus=143 
LimitNOFILE=65536 
Restart=always

[Install] 
WantedBy=multi-user.target
```

Then force the reload of the systemd configuration

```
// Some code
```