TensorRT-LLMs/docs/source/installation/linux.md

(linux)=

Installing on Linux via pip

1. Install TensorRT LLM (tested on Ubuntu 24.04).

   Install prerequisites

   Before the pre-built Python wheel can be installed via pip, a few prerequisites must be put into place:

   Install CUDA Toolkit 13.0 following the CUDA Installation Guide for Linux and make sure CUDA_HOME environment variable is properly set.

   The cuda-compat-13-0 package may be required depending on your system's NVIDIA GPU driver version. For additional information, refer to the CUDA Forward Compatibility.

   # By default, PyTorch CUDA 12.8 package is installed. Install PyTorch CUDA 13.0 package to align with the CUDA version used for building TensorRT LLM wheels.
   pip3 install torch==2.9.0 torchvision --index-url https://download.pytorch.org/whl/cu130
   
   sudo apt-get -y install libopenmpi-dev
   
   # Optional step: Only required for disagg-serving
   sudo apt-get -y install libzmq3-dev
   

   Instead of manually installing the preqrequisites as described
   above, it is also possible to use the pre-built [TensorRT LLM Develop container
   image hosted on NGC](https://catalog.ngc.nvidia.com/orgs/nvidia/teams/tensorrt-llm/containers/devel)
   (see [here](containers) for information on container tags).
   

   Install pre-built TensorRT LLM wheel

   Once all prerequisites are in place, TensorRT LLM can be installed as follows:

   pip3 install --upgrade pip setuptools && pip3 install tensorrt_llm
   

   This project will download and install additional third-party open source software projects. Review the license terms of these open source projects before use.

2. Sanity check the installation by running the following in Python (tested on Python 3.12):

       :language: python
       :linenos:
   

Known limitations

There are some known limitations when you pip install pre-built TensorRT LLM wheel package.

1. MPI in the Slurm environment

   If you encounter an error while running TensorRT LLM in a Slurm-managed cluster, you need to reconfigure the MPI installation to work with Slurm. The setup methods depends on your slurm configuration, pls check with your admin. This is not a TensorRT LLM specific, rather a general mpi+slurm issue.

   The application appears to have been direct launched using "srun",
   but OMPI was not built with SLURM support. This usually happens
   when OMPI was not configured --with-slurm and we weren't able
   to discover a SLURM installation in the usual places.
   

2. Prevent pip from replacing existing PyTorch installation

   On certain systems, particularly Ubuntu 22.04, users installing TensorRT LLM would find that their existing, CUDA 13.0 compatible PyTorch installation (e.g., torch==2.9.0+cu130) was being uninstalled by pip. It was then replaced by a CUDA 12.8 version (torch==2.9.0), causing the TensorRT LLM installation to be unusable and leading to runtime errors.

   The solution is to create a pip constraints file, locking torch to the currently installed version. Here is an example of how this can be done manually:

   CURRENT_TORCH_VERSION=$(python3 -c "import torch; print(torch.__version__)")
   echo "torch==$CURRENT_TORCH_VERSION" > /tmp/torch-constraint.txt
   pip3 install --upgrade pip setuptools && pip3 install tensorrt_llm -c /tmp/torch-constraint.txt