---
title: "Mount datasets and file systems on a VM"
description: "Mount TIR datasets, a Shared File System, and a Parallel File System on a TIR Virtual Machine, and learn where they appear and when the VM restarts."
content_type: "how-to"
product: "tir-vm"
platform: "TIR"
url: "/tir/tir-vm/how-to/mount-datasets-and-file-systems-on-a-vm/"
topic: ["data"]
---

# Mount datasets and file systems on a VM

Mount a dataset, a Shared File System (SFS), or a Parallel File System (PFS) on a TIR Virtual
Machine, and its data appears in a folder inside the VM. Datasets mount under `/datasets`, and an SFS
or a PFS mounts at a path you choose. A
dataset or an SFS mount is added again at every boot, so the folder is there each time the VM starts.

## Before you begin

- A VM in the project and region where your storage is, and permission to update VMs in the project.
  See [TIR Access Control](/tir/tir-iam/).
- A dataset that is ready or an SFS that is active, in that project and region, or a PFS whose
  **Storage Status** is **OK**. You can create each one from its tab on the VM's page, or in
  advance: for an SFS, see [Create an
  SFS](/tir/tir-sfs/how-to/create-an-sfs/).
- Your work saved. Mounting or unmounting a dataset, an SFS, or a PFS restarts a running VM.

Datasets, SFS, and PFS storage you mount are billed under their own products. They keep billing while the VM is stopped, and you delete them yourself to stop the charge. Deleting the VM detaches datasets and an SFS. They stay in your project, and you can mount them on another VM. For
prices, see [E2E's pricing page](https://www.e2enetworks.com/pricing).

## Choose what to mount

A dataset's **Storage Type** is **EOS Bucket** or **Disk**:

- A dataset in object storage (**EOS Bucket**) mounts read-only at `/datasets/<dataset-name>`.
  Choose it when the VM only reads the data.
- A disk dataset (**Disk**) mounts read-write at `/datasets/<dataset-name>`, on one VM at a time.
  Choose it when the VM needs to write to the data.
- A Shared File System is a shared, read-write file system that several VMs, instances, and the
  workers of a training job can mount at the same time. It mounts at the path you choose. Choose it
  when several machines need to read and write the same files together. A dataset is for data you
  mainly read.
- A Parallel File System mounts at the path you choose, and it is available in Delhi. To choose between a PFS and an SFS, see [Parallel File
  System](/tir/tir-pfs/).

## Mount storage when you create a VM

On the **Create VM** form, under **Storage**, the optional **Other storage** offers **Shared File
System**, **Datasets**, and in Delhi **Parallel File System**. Choose the ones to mount, and for an SFS or a PFS also type a mount path that follows the
[mount path rules](#mount-path-rules), such as `/my-sfs` or `/my-pfs`. To mount a PFS read-only, tick **Read
Only**. For a dataset or SFS you still need
to make, its **Click here** link opens the create page in a new tab. See [Create a VM](/tir/tir-vm/how-to/create-a-vm/)
for the rest of the form.

## Mount or unmount a dataset

1. In **Manage VMs**, select the VM's name, then select the **Associated Datasets** tab.
2. Tick each dataset to mount, and clear each one to unmount.
3. Select **Update**. The change restarts the VM, so tick "Are you sure you want to continue
   updating datasets?" and select **Update** again.

The VM restarts, and each dataset's **State** is **Mounted** or **Unmounted** when it is back.

A disk dataset mounts on one VM at a time. To use one that is mounted on another VM, unmount it there
first.

## Mount or unmount a Shared File System

1. In **Manage VMs**, select the VM's name, then select the **Shared File-System** tab.
2. In the SFS's row, type a **Mount Path** that follows the [mount path rules](#mount-path-rules),
   then select **Mount**.
3. Mounting restarts the VM. In **Mounting SFS**, tick "Are you sure you want to continue mounting
   SFS?" and select **Continue**.

The VM restarts, and the file system is **Mounted** when it is back. You mount one SFS at a time.

To unmount, select **Unmount** in the SFS's row and confirm the same way. The VM restarts without it.

## Mount or unmount a Parallel File System

Parallel File Systems are available in Delhi.

1. In **Manage VMs**, select the VM's name, then select the **Parallel File-System** tab.
2. In the PFS's row, type a **Mount Path** that follows the [mount path rules](#mount-path-rules).
   To mount it read-only, tick **Read Only**. Then select **Mount**. A PFS mounts once its
   **Storage Status** is **OK**.
3. Mounting restarts the VM. In **Mounting PFS**, tick "Are you sure you want to continue mounting
   PFS?" and select **Continue**.

The VM restarts, and the PFS is **Mounted** when it is back. To unmount, select
**Unmount** in the same row, and confirm in the **Unmounting PFS** dialog the same way.

Any user on the VM can read or write a mounted PFS according to the owner, group, and other
permissions of each file and folder. For sizing, deleting, and what is using a PFS, see [Parallel
File System](/tir/tir-pfs/).

## Mount path rules

The mount path of an SFS or a PFS must:

- start with `/` and not end with `/`
- use only letters, digits, hyphens, and underscores, with no `//`
- differ from the path of any SFS or PFS already mounted on the VM

The paths `/home/jovyan`, `/mnt/local`, `/datasets`, and anything under `/datasets/` are
reserved, so choose another path. A path that matches a mounted SFS or PFS is refused with "file system path
already mounted". Mounting an SFS that is already mounted returns "SFS is already mounted", and mounting a
PFS that is already mounted fails with "pfs already mounted".

## Check the mounted folders

Once the VM is **Running** again, connect to it over SSH, as described in [Connect to a VM over
SSH](/tir/tir-vm/how-to/connect-to-a-vm-over-ssh/), and list the folder:

```bash
ls /datasets/<dataset-name>
```

Replace `<dataset-name>` with the dataset's name. For an SFS or a PFS, list the mount path you typed.

## If a mount fails

A dataset must be ready and in the VM's project and region. Otherwise, the mount is refused with "Some of the
datasets are either invalid or not ready". A mount that fails returns "Error while mounting/unmounting datasets on
notebook". For help with these messages, see [Troubleshooting TIR Virtual
Machines](/tir/tir-vm/troubleshooting/tir-vm/#a-dataset-or-a-shared-file-system-will-not-mount).

To create or manage a file system, see [TIR Shared File System](/tir/tir-sfs/) and [Parallel File
System](/tir/tir-pfs/).