# EMF PSI

The storage systems used by the Electron Microscopy Facility at PSI (EMF) are mounted on the Merlin 7 login nodes. You can copy files from the EMF storage to your home or project directory on Merlin 7, or transfer them from Merlin 7 to your local computer.

## Within Merlin 7

The EMF files are accessible through the `/emf` mount on the Merlin 7 cluster. However, the files are **not stored on Merlin 7**; the mount provides access to files that remain on the EMF storage system.

Before working with the files, copy them to your home directory or project directory on Merlin 7.

### `rsync`

We recommend using `rsync` to copy files because it preserves file attributes and provides useful information about the transfer.

Run:

```bash
rsync -avAHXS sourcedir/ destdir/
```

If you need to change the group ownership of the copied files, use:

```bash
rsync -avAHXS --chown=:$GROUP_NAME sourcedir/ destdir/
```

Replace `$GROUP_NAME` with the name of the group that should own the files.

!!! note
    The trailing `/` in `sourcedir/` is significant. It means that the **contents** of `sourcedir` are copied to `destdir`, rather than the directory itself.

### `cp`

Alternatively, you can use `cp`:

```bash
cp -r sourcedir/ destdir/
```

## From Merlin 7 to your local machine

You can transfer files from Merlin 7 to your local computer using `rsync`, `scp`, or a graphical application such as FileZilla.

### `rsync`

`rsync` is recommended for transferring large amounts of data or for transfers that may need to be resumed.

For example:

```bash
rsync -avAHXS $USER@login001.merlin7.psi.ch:/data/project/general/myproject/ ~/localdata/
```

### `scp`

For a simple recursive copy, you can use `scp`:

```bash
scp -r $USER@login001.merlin7.psi.ch:/data/project/general/myproject/ ~/localdata/
```

### FileZilla

You can also use [FileZilla](https://filezilla-project.org/) to transfer files between your local computer and Merlin 7.

Open FileZilla and create a connection to Merlin 7 using the following settings:

| Setting      | Value                                                  |
| ------------ | ------------------------------------------------------ |
| **Host**     | `login001.merlin7.psi.ch` or `login002.merlin7.psi.ch` |
| **Username** | Your Merlin 7 username                                 |
| **Password** | Your Merlin 7 password                                 |
| **Port**     | `22`                                                   |
| **Protocol** | `SFTP - SSH File Transfer Protocol`                    |

Once connected, the files on Merlin 7 will be displayed in the **Remote site** panel.

You can transfer files between your computer and Merlin 7 by dragging them between the **Remote site** and **Local site** panels. Alternatively, right-click a file or directory and select **Download** or **Upload**.

!!! tip
    To improve file transfer speeds, increase the maximum number of simultaneous transfers in FileZilla:

    1. Open **Edit > Settings**.
    2. Select **Transfers**.
    3. Under **Maximum simultaneous transfers**, set **Maximum simultaneous transfers** to `10`.
    4. Click **OK** to save the changes.

    ![FileZilla transfer settings](../../images/CLS/data_transfer/data_transfer_tips.png)