Extracting Data from a RAID Disk When NAS TerraMaster U12-420 is Not Starting: Comprehensive Guide

Contents

• Why Regular Data Recovery Tools Can’t Restore Files from RAID
• Key Information About the NAS TerraMaster U12-420
• How to Remove Hard Disks from Your NAS and Connect Them to a PC
  • Step-by-Step Data Recovery with Hetman RAID Recovery
  • How to Safely Recover Data from Disk Images
  • Where Are the User’s Files Actually Stored?
  • RAID Recovery Software: Detailed Comparison

Why Regular Data Recovery Tools Can’t Restore Files from RAID

Conventional hard drives store user data by writing it sequentially across the disk surface, which means an entire file is typically located on a single drive. In contrast, when data is written to a RAID array, each file is split into multiple fragments. These fragments are then distributed and written in sequence across all the drives in the array. Depending on the configuration, fragment sizes can range from 2 KB to 2 MB, so every file is physically stored across several disks at once.

This approach significantly increases read and write performance — after all, writing two halves of a 1 GB file to two drives simultaneously is much faster than writing the full 1 GB to a single disk. However, this same mechanism makes file recovery far more complex.

Different RAID levels use different methods to distribute and protect data. On top of that, manufacturers like TerraMaster often add their own proprietary structures and variations. As a result, data can be written to disks in many different formats, and each requires a specific approach during recovery.

How can a NAS TerraMaster U12-420 device's power management settings impact data availability and potential loss?

The power management settings of a NAS TerraMaster U12-420 device can have a significant impact on data availability and potential loss. Here are a few ways in which power management settings can affect data:

1. System Shutdown: If the power management settings are configured to automatically shut down the NAS device after a certain period of inactivity, it can lead to data unavailability. If the NAS shuts down while users are accessing or transferring data, it can result in interrupted connections and potential loss of unsaved or uncommitted data.
2. Scheduled Power On/Off: Some NAS devices allow users to schedule automatic power on and power off times. If the power management settings are not properly configured or synchronized with user activity, it can result in data unavailability during critical work hours. For example, if the NAS is set to power off during a backup process or a data synchronization operation, it can lead to incomplete or failed tasks.
3. Power Loss Protection: Some NAS devices offer power loss protection mechanisms, such as battery backup or surge protection. If the power management settings do not properly utilize or configure these features, sudden power outages or voltage fluctuations can result in data loss or corruption. It is crucial to ensure that the power management settings are optimized to utilize these protective mechanisms effectively.
4. Disk Spinning and Sleep Modes: NAS devices often have power management settings that control the spinning of hard drives or put them into sleep mode after a certain period of inactivity. While these settings can save power, they can also impact data availability. If the drives take too long to spin up or wake from sleep mode when a user tries to access data, it can result in delayed response times and user frustration. Additionally, frequent spin-up and spin-down cycles can reduce the lifespan of hard drives, increasing the risk of data loss due to drive failures.

To mitigate the impact of power management settings on data availability and potential loss, it is important to carefully configure and test these settings based on the specific requirements of the NAS device and the data usage patterns. Regular backups, redundant storage configurations, and UPS (Uninterruptible Power Supply) systems can also provide additional safeguards against data loss in case of power-related issues.

How to Remove Hard Disks from Your NAS and Connect Them to a PC

Although the NAS U12-420 can be accessed over the network, you still need to remove its hard disks and connect them directly to a Windows PC. Only then can the recovery software properly scan and analyze the drives. Follow these steps:

1. Power off the NAS and disconnect it from the power source.

   WARNING! Before removing any drives, carefully read the device manual. Improper actions may damage both the NAS enclosure and the hard disks in the RAID array.

2. Remove the hard disks one by one, gently sliding each drive out of its slot. Remember that hard disks are highly sensitive: any impact or drop can cause serious physical damage.

3. Label each hard disk according to its position inside the NAS. The order of the drives is crucial for correct RAID reconstruction.

4. Connect the drives to your computer. In this video, we explain which ports you can use to connect hard disks and what to do if your PC does not have enough free connectors.

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   How to Order Remote Data Recovery

Step-by-Step Data Recovery with Hetman RAID Recovery

This program restores data from damaged RAID arrays and is fully compatible with TerraMaster U12-420. Each hard disk in the array contains technical metadata describing how files were written. When launched, Hetman RAID Recovery analyzes this metadata, automatically reconstructs the damaged array, and provides access to its contents. After that, you can browse the recovered disk and save your files. The program can also restore files that were accidentally deleted from the network drive.

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How to recover data from a TerraMaster

U12-420 has 12 HDD slots, and it supports the following array types:

• RAID 0;
• RAID 1;
• RAID 5;
• RAID 6;
• RAID 50;
• RAID 60;
• JBOD;

NAS supports:

• Ext2;
• Ext3;
• Ext4;
• Btrfs;

How to Safely Recover Data from Disk Images

This utility allows you to create a complete copy of a disk and work with the disk image instead of the physical drive. This approach helps protect your data from:

• Overwriting during the recovery process;
• Additional data loss caused by bad sectors;
• User errors.

To create a disk image, follow these steps:

1. Ensure you have enough free space to store the image. Its size will typically match the size of the original disk.

2. In the main window, select the target disk and choose Tools - Save Disk. You can also select multiple disks if needed.

3. When the Image Creation Wizard opens, select whether you want to save the entire disk or only a specific region. Adjust the settings and click Next.

   

4. Choose the directory where the image will be saved. You may select any available disk connected to your PC or upload the image via FTP.

   

Where Are the User’s Files Actually Stored?

The TerraMaster U12-420 network-attached storage keeps OS Linux operating system files on a separate RAID 1 (mirrored) array. Usually, all NAS systems create several volumes on every hard disk, and the first of them takes up to 2 Gb of space. This is where operating system files are stored. Other volumes are united into a RAID array where user’s data is written.

RAID Recovery Software: Detailed Comparison