Nextflow Parameters

This page gives an overview of Nextflow parameters that can be used to control the pipeline execution.

note

These options are part of Nextflow and use a single hyphen, - (pipeline parameters use a double-hyphen, --).

-profile

Use this parameter to choose a configuration profile. Profiles can give configuration presets for different compute environments.

Several generic profiles are bundled with the pipeline which instruct the pipeline to use software packaged using different methods (Docker, Singularity, Podman, Shifter, Charliecloud, Conda) - see below. When using BioContainers, most of these software packaging methods pull Docker containers from quay.io e.g FastQC except for Singularity which directly downloads Singularity images via https hosted by the Galaxy project and Conda which downloads and installs software locally from Bioconda.

info

We highly recommend the use of Docker or Singularity containers for full pipeline reproducibility, however when this is not possible, Conda is also supported.

The pipeline also dynamically loads configurations from https://github.com/nf-core/configs when it runs, making multiple config profiles for various institutional clusters available at run time. For more information and to see if your system is available in these configs please see the nf-core/configs documentation.

Note that multiple profiles can be loaded, for example: -profile test,docker - the order of arguments is important! They are loaded in sequence, so later profiles can overwrite earlier profiles.

If -profile is not specified, the pipeline will run locally and expect all software to be installed and available on the PATH. This is not recommended.

• docker
  • A generic configuration profile to be used with Docker
• singularity
  • A generic configuration profile to be used with Singularity
• apptainer
  • A generic configuration profile to be used with Apptainer
• podman
  • A generic configuration profile to be used with Podman
• conda
  • A generic configuration profile to be used with Conda. Please only use Conda as a last resort i.e. when it's not possible to run the pipeline with Docker, Singularity, Podman, Shifter or Charliecloud.
• mamba
  • A generic configuration profile to be used with Mamba. Mamba is a drop-in replacement for Conda that is faster and more reliable.
• test
  • A profile with a complete configuration for automated testing
  • Includes links to test data so needs no other parameters

warning

Since Nextflow 23.07.0-edge, Nextflow no longer mounts the host's HOME directory when using Apptainer or Singularity. Some dependencies of old pixelator versions (<=0.15.x) needed HOME directory write access, thus causing issues. As a workaround, you can revert to the old behavior by setting the environment variable NXF_APPTAINER_HOME_MOUNT or NXF_SINGULARITY_HOME_MOUNT to true in the machine from which you launch the pipeline.

-resume

Specify this when restarting a pipeline. Nextflow will use cached results from any pipeline steps where the inputs are the same, continuing from where it got to previously. For input to be considered the same, not only the names must be identical but the files' contents as well. For more info about this parameter, see this blog post.

You can also supply a run name to resume a specific run: -resume [run-name]. Use the nextflow log command to show previous run names.

-c

Specify the path to a specific config file (this is a core Nextflow command). See the nf-core website documentation for more information.