> 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/disk-initialization.md).

# Disk Initialization

This guide explains the recommended first-time disk initialization sequence for IODD devices. Use it when installing a new HDD or SSD, preparing AES256 encryption before formatting, selecting MBR or GPT, or checking voltage before normal use.

For OS-level partitioning and file system formatting details, also see [IODD Drive Initialization](/troubleshooting/iodd-drive-initialization.md).

## 1. First-Time Setup Sequence

If you are installing a new disk for the first time, follow this specific order:

1. **Detection:** Once the IODD is recognized, an initialization message will appear in your OS disk management tool.
2. **Encryption First (Optional):** \* If you intend to use hardware encryption, you **must set the password on the IODD hardware first** before initializing the drive in Windows/Mac.
   * **ST400, LK100 & MINI PRO:** Set the **2nd Password first**, followed by the **1st Password**.
3. **Perform Full TRIM (Highly Recommended):** Before creating partitions, we strongly recommend running the [**IODD TRIM Tool**](/various-functions/iodd-trim-tool.md) to perform a **Full Device TRIM**. This ensures all flash memory blocks are properly initialized to a clean state, providing optimal write speeds and extending the SSD's lifespan. *(If you have already created partitions or are currently using the drive, you can use the **Free Space Only TRIM** feature to safely optimize it without losing data.)*
4. **Disk Initialization:**
   * **Modern Models (ST, MINI PRO, LK100):** Supports both **MBR** and **GPT**. GPT is recommended for drives over 2TB.
   * **Legacy Models (2531, 2541, MINI Legacy):** Supports **MBR only**. GPT is **not supported**.
   * **Note:** Legacy models have a hardware limit that only recognizes the first **2TB** of a drive.
5. **Partitioning & Formatting:**
   * Format using **NTFS, exFAT, or FAT32**.
   * **Note:** FAT32 has a 4GB file size limit. NTFS/exFAT is recommended for ISO/VHD files.
   * **VHD Tool++ note:** If you use VHD Tool++, **exFAT** is recommended. On some Windows versions/locale settings, NTFS may cause occasional time/timestamp format errors in the tool.
   * **ST/MINI PRO:** The IODD data partition does not have to be the first partition on the disk.
6. **Safe Removal (Crucial):** Always use **Safely Remove Hardware** before disconnecting. Failure to do so with NTFS can lead to the "ASSERT" error.
7. **Reconnect & Verify:** Reconnect the IODD.
   * **Modern Models (ST, MINI PRO, LK100):** If files are not visible, **hold the \[4] key for 3 seconds** to manually select the correct partition.
   * **Legacy Models (2531, 2541, MINI Legacy):** This partition selection hotkey is **not supported**. Ensure your data is on the first primary partition. (For 2541, long-pressing \[4] only rescans the current partition).

***

## 2. Fixing Initialization Failures (MBR to GPT to MBR Trick)

If the drive fails to initialize or displays errors, try this cycle:

1. Connect the HDD/SSD directly to a PC (if possible) or via IODD.
2. Initialize it as **GPT**.
3. Then, immediately re-initialize it back to **MBR**. This process can often clear corrupted partition table metadata that simple formatting cannot fix.

***

## OS Specific Guides

* **Windows:** [Microsoft Disk Management Guide](https://learn.microsoft.com/en-us/windows-server/storage/disk-management/initialize-new-disks).
* **macOS:** [Disk Utility User Guide](https://support.apple.com/en-au/guide/disk-utility/dskutl1010/mac).

***

## 3. Voltage Check

Monitoring voltage is crucial for data integrity. Press **\[3]** on the keypad to view the current **V-voltage**.

* **Lowest/Minimum Voltage**: Some models (ST/2541) track the lowest voltage detected since connection. This is the most critical value for stability.
* **Current Voltage**: Displays the real-time BUS voltage.

{% hint style="danger" %}
**Low Voltage Warning (< 4.65V)** This is critical. Large file transfers may fail, or the disk may disconnect randomly. You **must** move to a rear PC port or use a **powered USB hub** immediately to prevent data loss.
{% endhint %}