> For the complete documentation index, see [llms.txt](https://help.iodd.kr/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://help.iodd.kr/bootable-virtual-drive/virtual-drive-vhd/create-vhd-file-with-vhd-tools.md).

# Create VHD file with VHD Tools

#### Overview of Virtual Drive Creation

The VHD Tool is a **Windows-exclusive application** designed to create fixed-size VHD files, allowing your IODD device to function as a virtual drive.

{% hint style="info" %}
**Supported File Systems** The VHD Tool supports both **NTFS** and **exFAT** partitions for VHD creation.

**Recommended:** Use **exFAT**. VHD Tool++ relies on Microsoft's legacy `vhdtool.exe`, and on some Windows versions/region settings you may encounter occasional **time/timestamp format errors** when working on an NTFS partition.
{% endhint %}

#### Download VHD Tools

<details>

<summary>View Download Link</summary>

[Official IODD Download Center (https://dir.iodd.kr/)](https://dir.iodd.kr/)

**Tip**: To force the English version of the application, run the **`VHD_Tool++(en).bat`** file instead of the standard EXE.

</details>

#### Step-by-Step VHD Creation

1. Launch the **VHD Tool** application.
2. Navigate to the top menu and select the **\[Create]** tab.

   <figure><img src="/files/2Eq6ULaJ7WnBZK7GKxAY" alt="VHD Tool Create Tab"><figcaption><p>Initiate new virtual drive setup via the Create menu.</p></figcaption></figure>
3. In the **\[File name]** field, designate the save path (an NTFS or ExFAT partition on the IODD) and enter the desired filename.

   <figure><img src="/files/gsc6JU1asQSl7WIdJkBX" alt="File Path Selection"><figcaption><p>Select the internal IODD directory where the file will be stored.</p></figcaption></figure>
4. Enter the required capacity for the VHD file in the **\[Size]** field.

{% hint style="warning" %}
The allocated size must be less than or equal to the **\[Biggest linear Space]** (maximum contiguous free space) available on the disk.
{% endhint %}

<figure><img src="/files/BVZ7cBWuK4HJssBXd2k8" alt="VHD Size Configuration"><figcaption><p>Assign the appropriate capacity after verifying the available disk space.</p></figcaption></figure>

5\. Click the \*\*\[Create]\*\* button at the bottom to begin generating the VHD file in the specified path.

{% hint style="warning" %}
**UEFI Installation Requirements** When creating a VHD for UEFI booting and installation purposes, the VHD file size must be larger than the size of the original ISO file.
{% endhint %}

{% hint style="info" %}
**Disk Optimization Recommended** Creating a VHD requires contiguous disk space. If creation fails due to insufficient contiguous space, please perform a **disk defragmentation** and try again.
{% endhint %}

***

#### Mounting and Persisting the VHD State

Once the creation process is complete, follow these steps to mount the VHD and ensure it remains loaded after a reboot.

1. Reconnect the IODD device to your PC.
2. Use the LCD screen on the IODD to locate and select the newly created VHD file.
3. Press the **\[6]** button or the **\[Enter]** key to mount the file.
4. **Important (Save State):** To maintain the mount status even after a reboot or reconnection, you must press the **\[9]** key (or **\[Enter]** for certain models) to **save the current state** before restarting your PC.

{% hint style="warning" %}
**Persisting Mount Status** If you do not save the state using the **\[9]** key, the VHD will be unmounted when the device loses power or the PC reboots. Ensure you save the state before proceeding to the boot sequence.
{% endhint %}

{% hint style="danger" %}
**Troubleshooting Mount Failures** The VHD will not mount if the Virtual Drive mode is disabled in the device settings. Please refer to the [Mode Configuration Guide](/bootable-virtual-drive/mode-configuration.md) to verify your configuration.
{% endhint %}

***

#### 🛠️ Advanced VHD Tool++ Functions

Beyond simple creation, VHD Tool++ provides several utility functions for managing virtual drives:

* **\[Convert]**: Converts a general disk dump image file into a fixed-size VHD file.
* **\[Extend]**: Increases the size of an existing fixed VHD file.
* **\[Defragment]**: Specifically defragments a single file on the IODD to ensure it is contiguous (0 fragments).
* **\[Upload]**: Copies a file from your PC to the IODD while ensuring it remains unfragmented during the transfer.
* **\[Write To HDD] (Expert Only)**: Performs a sector-to-sector physical duplication of an image file to the internal HDD. **Note**: This function only supports the **NTFS** file system.
  * <div data-gb-custom-block data-tag="hint" data-style="danger" class="hint hint-danger"><p><strong>WARNING</strong>: This will permanently delete ALL data on the internal drive. It is only recommended for advanced users performing raw disk operations.</p></div>