calcua

CalcUA (VSC Antwerp)

This guide is for running Metatropics on CalcUA, the Tier‑1 HPC at VSC Antwerp. On a cluster you normally submit a job with a script instead of starting Nextflow by hand on a login node; the .sbatch files here do that and point Metatropics at storage and containers in a way that fits CalcUA. Under the hood they use Slurm (the scheduler), Apptainer (containers on HPC), and the Nextflow profiles vsc_calcua or vsc_calcua_gpu.

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How to run

1. Clone and configure — Clone the Metatropics repository and set up params_fastq.yaml or params_POD5.yaml as in the repository root README.
2. Edit the .sbatch you need — Set #SBATCH (account, partition, walltime), PIPELINE_DIR, and PARAMS_FILE if they differ from the defaults.
3. Submit from the Metatropics repository root (the folder that contains nf-metatropics/). Pick the script that matches your input, then run the matching sbatch command below.

Your input	Script	Params file (typical)	Nextflow profile
FASTQ	submit_metatropics_fastq_calcua.sbatch	params_fastq.yaml	vsc_calcua (CPU)
POD5	submit_metatropics_pod5_calcua.sbatch	params_POD5.yaml	vsc_calcua_gpu (GPU + CPU)

# FASTQ
sbatch nf-metatropics/assets/calcua/submit_metatropics_fastq_calcua.sbatch

# POD5 + Dorado (GPU)
sbatch nf-metatropics/assets/calcua/submit_metatropics_pod5_calcua.sbatch

Configs used by those profiles: ../../conf/vsc_calcua_cpu.config, ../../conf/vsc_calcua_gpu.config.

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Additional details

Optional reading: partitions, caches, and where to tune resources.

Apptainer caches — Images are pulled when needed and cached under scratch (NXF_APPTAINER_CACHEDIR in the .sbatch). The script prefers the job’s $TMPDIR for APPTAINER_TMPDIR when present (else scratch) to reduce tmp-quota issues during Docker→SIF conversion.

GPU partitions (Dorado / CUDA) - Usual GPU queues on CalcUA (Vaughan / Leibniz). Confirm with sinfo -o '%P %G %l %m' and the VSC Antwerp hardware docs; access depends on your project.

Partition	GPU	GPU memory	GPUs/node	Max walltime
ampere_gpu	NVIDIA A100	40 GB	4	1 day
pascal_gpu	NVIDIA P100	16 GB	2	1 day
arcturus_gpu	AMD MI100	32 GB	2	1 day

Dorado is NVIDIA/CUDA: use ampere_gpu or pascal_gpu, not arcturus_gpu. To change GPU queue or Slurm GPU flags, edit calcua_gpu_slurm_partition and calcua_gpu_cluster_options in ../../conf/vsc_calcua_gpu.config, then submit with submit_metatropics_pod5_calcua.sbatch.

CPU/RAM for Dorado — DORADO_* processes use the process_gpu label. Defaults in ../../conf/base.config; CalcUA POD5 tuning in ../../conf/vsc_calcua_gpu.config (with GPU partition / --gres). GPU allocation follows calcua_gpu_cluster_options. The Dorado image is pulled from Docker Hub and cached as a SIF under NXF_APPTAINER_CACHEDIR like other images.

CPU partitions — With profile vsc_calcua, these CPU partitions are supported (max per-task resources):

Partition	Max CPU	Max RAM	Max walltime
zen2	64	240 GB	3 days
zen3	64	240 GB	3 days
zen3_512	64	496 GB	3 days
broadwell	28	112 GB	3 days
broadwell_256	28	240 GB	3 days
skylake	28	176 GB	7 days

In Slurm-scheduled mode these are limits for individual pipeline tasks; for single_node runs they are effectively up to what you requested in sbatch (see comments in the FASTQ .sbatch). Process labels are tuned conservatively in ../../conf/vsc_calcua_cpu.config so the same run can work across these partitions.

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