> ## Documentation Index
> Fetch the complete documentation index at: https://docs.komodo.io/llms.txt
> Use this file to discover all available pages before exploring further.

# Storage

## Overview

Komodo supports reading/writing to cloud object storage buckets on your machines/jobs/services.

The following object storage providers are currently supported:

* Amazon S3
* Google Cloud Storage (GCS)
* Azure Blob Storage

<Note>To use these providers, you will first need to [connect your cloud account](tutorials/connecting-clouds/overview)</Note>

There are 2 modes for using storage buckets:

1. COPY - copies the contents of the bucket to a specific location on the instance. This is helpful for datasets where you need fast read access. Any files written here will NOT be uploaded back to the bucket.
2. MOUNT - mounts the bucket as a file system on the instance. This is helpful for having a perisistent storage location, where you can store your model checkpoints and access them even after your tasks finish. Any files written here will be uploaded back to the bucket.

Here is an example of what you'd need to include in your task config to effectively use cloud storage buckets:
Here is how you can use cloud storage from different providers:

<Tabs>
  <Tab title="Amazon S3">
    ```yaml theme={null}
    file_mounts:
      # Copy the contents of an S3 bucket to /dataset
      /dataset:
        source: s3://my-dataset
        mode: COPY

      # Mount an S3 bucket to /output
      # Any files written here (eg. model checkpoints) will be uploaded back
      # to the S3 bucket
      /output:
        source: s3://my-output-bucket
        mode: MOUNT
    ```
  </Tab>

  <Tab title="Google Cloud Storage">
    ```yaml theme={null}
    file_mounts:
      # Copy the contents of a GCS bucket to /dataset
      /dataset:
        source: gs://my-dataset
        mode: COPY

      # Mount a GCS bucket to /output
      # Any files written here (eg. model checkpoints) will be uploaded back
      # to the GCS bucket
      /output:
        source: gs://my-output-bucket
        mode: MOUNT
    ```
  </Tab>

  <Tab title="Azure Blog Storage">
    ```yaml theme={null}
    file_mounts:
      # Copy the contents of an Azure Blog Storage container to /dataset
      /dataset:
        source: https://<account name>.blob.core.windows.net/<container name>
        mode: COPY

      # Mount an Azure Blog Storage container to /output
      # Any files written here (eg. model checkpoints) will be uploaded back
      # to the container
      /output:
        source: https://<account name>.blob.core.windows.net/<container name>
        mode: MOUNT
    ```
  </Tab>
</Tabs>

## Picking a storage mode

<br />

|                        | MOUNT                                                                                         | COPY                                                            |
| ---------------------- | --------------------------------------------------------------------------------------------- | --------------------------------------------------------------- |
| **Best For**           | Writing task outputs (eg. checkpoints, logs), reading very large data that won't fit on disk. | High performance read-only access to datasets that fit on disk. |
| **Performance**        | Slow to read/write files. Fast to provision.                                                  | Fast file access. Slow at initial provisioning.                 |
| **Writing to buckets** | Most write operations are supported.                                                          | Not supported, read-only.                                       |
| **Disk Size**          | No disk size requirements.                                                                    | Disk size must be greater than the size of the bucket.          |