---
title: "Mount a PFS on a training cluster"
description: "Mount one or more TIR Parallel File Systems on every worker of a training cluster or a Slurm cluster, at the paths you choose."
content_type: "how-to"
product: "tir-pfs"
platform: "TIR"
url: "/tir/tir-pfs/how-to/mount-a-pfs-on-a-training-cluster/"
topic: ["create-and-connect"]
---

# Mount a PFS on a training cluster

Mount one or more PFS on every worker of a training cluster or a Slurm cluster. Each worker reads
and writes at the paths you choose, ready for parallel access during the job.

## Before you begin

You need a PFS in status **OK**, in the same project as the cluster; see [Create a
PFS](/tir/tir-pfs/how-to/create-a-pfs/). The cluster's create screen lists every PFS in the
project, and you can select the ones that read **OK**.

## Choose the PFS when you create the cluster

On the create screen for a training cluster or a Slurm job, select one or more PFS to mount on every
worker. Give each one its own mount path. A path must be unique across the Datasets, SFS, and PFS you
choose for that cluster.

A training cluster job of the Slurm type needs at least one SFS or PFS selected; for other training
cluster jobs, one is optional.

A [TIR Slurm Cluster](/tir/tir-slurm-cluster/) takes a PFS on its own create form, alongside SFS volumes
and datasets, and mounts it on the login node as well as every worker. To add or remove one there, see
[Mount and unmount volumes](/tir/tir-slurm-cluster/how-to/mount-and-unmount-volumes/).

## Check what is mounted

After the cluster is created, its **Volumes** tab lists the PFS mounted on it, and you can filter
the list to mounted or unmounted. The PFS's own **Services** tab shows the same list under
**Training Cluster Deployments**; see [See what uses a PFS](/tir/tir-pfs/how-to/see-what-uses-a-pfs/).

Design the job to read and write in parallel across its workers. Use larger blocks for sequential
transfers, so the job uses a PFS's bandwidth fully.

When a job needs more space, [increase the size of a PFS](/tir/tir-pfs/how-to/increase-the-size-of-a-pfs/), or [mount the same PFS on an instance](/tir/tir-pfs/how-to/mount-a-pfs-on-an-instance/) as
well. For help with a path conflict or another message while you create the cluster, see
[Troubleshooting TIR Parallel File System](/tir/tir-pfs/troubleshooting/tir-pfs/).