---
title: "Mount a disk on an instance"
description: "Attach a TIR Block Storage disk to an instance or Virtual Machine by mounting it, so the instance reads and writes it at /datasets/<name>."
content_type: "how-to"
product: "tir-block-storage"
platform: "TIR"
url: "/tir/tir-block-storage/how-to/mount-a-disk-on-an-instance/"
topic: ["connect"]
---

# Mount a disk on an instance

Mount a disk on an instance or a Virtual Machine to use it as storage that the instance reads and
writes. A disk mounts on one instance at a time.

## Before you begin

- A disk whose **Status** is **Ready**. See [Create a disk](/tir/tir-block-storage/how-to/create-a-disk/).
- An instance or Virtual Machine in the same project and region, and a role that lets you update
  instances.
- Your work saved. Mounting on a running instance restarts it, and a stopped instance picks up the
  change at its next start. On a container instance, reinstall any packages you installed by
  hand once it restarts.
- The disk unmounted from any other instance. If another instance holds it, [unmount it
  there](/tir/tir-block-storage/how-to/unmount-a-disk-from-an-instance/) first. A stopped instance
  keeps holding a disk until you unmount it.

## Mount the disk

1. Open the instance's page and select the **Associated Datasets** tab. It lists the datasets in
   the project and region.
2. Tick the disk. You can tick only a disk that no other instance holds. For a held disk, the tab says "This disk
   dataset is already mounted on other node". On a Virtual Machine it says **VM** instead of
   **node**.
3. Select **Update**.
4. Tick **Are you sure you want to continue updating datasets?** and select **Update** again.

To mount the disk when you create the instance, open **Storage** > **Other storage** > **Datasets**
on the **Create Instance** form and pick the disk. It mounts when the instance starts. See
[Create an instance](/tir/tir-instance/how-to/create-an-instance/).

## Check the mount

When the instance is **Running** again, the disk shows **Mounted** on the **Associated Datasets**
tab. It appears in the instance at `/datasets/<name>`, where `<name>` is the disk's **Dataset Name**, and you can
read and write it. To see it, open a terminal and list the folder:

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

A disk mounts on an instance or a Virtual Machine only. The dataset lists for Training Cluster,
training job, Slurm Cluster, and model endpoint offer only Object Storage datasets, so use [TIR Object
Storage](/tir/tir-object-storage/) there. When you delete an instance, a disk mounted on it is
unmounted and stays in your disk list.

To get files onto the disk, see [Put data on a disk](/tir/tir-block-storage/how-to/put-data-on-a-disk/).
For help with a refused mount, see [Troubleshooting TIR Block Storage](/tir/tir-block-storage/troubleshooting/tir-block-storage/).