How to recover data from TerraMaster U8-420 NAS

Contents

• Why can’t ordinary software tools restore files from RAID?
• How to take hard disks out of the NAS and connect them to a PC?
  • Restoring data with Hetman RAID Recovery
  • Safe recovery from disk images
  • Where are user’s files stored?
  • Comparison of software for RAID recovery

Why can’t ordinary software tools restore files from RAID?

Conventional hard disks keep user’s data by writing it to their surface in a consecutive way, and this is how an entire file is stored on a single hard disk. However, when data is written to a RAID system, a file is divided into several parts. Then these parts are written consecutively to all hard disks within such array. The size of such parts may range from 2 KB to 2 MB, so each file is stored on several hard disks at the same time.

Such approach helps to speed up read and write operations, and it is evident that saving two parts of a file having the size of 1 GB to two hard disks simultaneously is much faster than saving the same 1 GB of data to one hard disk. However, this peculiarity makes file recovery more complicated.

Various RAID levels store information in different ways. Additionally, manufacturers like TerraMaster also introduce some modifications to this process, and that is why data can be written to hard disk in a wide variety of ways.

How can RAID (Redundant Array of Independent Disks) configurations impact data loss in NAS TerraMaster U8-420 devices?

RAID configurations can have a significant impact on data loss in NAS TerraMaster U8-420 devices. Here are a few ways RAID can affect data loss:

1. Redundancy: RAID configurations, such as RAID 1, RAID 5, or RAID 6, provide redundancy by distributing data across multiple disks. In the event of a disk failure, the redundant data allows for the reconstruction of lost data. This reduces the risk of data loss as long as the failed disk is replaced and the array is rebuilt promptly.
2. Data protection: RAID configurations offer various levels of data protection. For example, RAID 1 mirrors data across two disks, ensuring that if one disk fails, the other contains an exact copy. Similarly, RAID 5 and RAID 6 use parity information to protect against a single or multiple disk failures. These configurations enhance data integrity and minimize the chances of data loss.
3. Hot-swapping: Many NAS devices, including TerraMaster U8-420, support hot-swapping, which allows for the replacement of a failed disk without shutting down the system. This feature reduces the downtime during disk replacement and ensures continuous data availability.
4. Rebuild process: When a failed disk is replaced, the RAID array initiates a rebuild process to restore data redundancy. During this process, data is reconstructed from the remaining disks or parity information. However, the rebuild process can be resource-intensive and time-consuming, increasing the risk of data loss if another disk fails during the rebuild. It is crucial to monitor the rebuild process and address any issues promptly.
5. RAID controller failure: While RAID configurations provide data protection against disk failures, they are still vulnerable to RAID controller failures. If the RAID controller malfunctions, it can lead to data loss or corruption across the entire array. Regular backups and monitoring of the RAID controller's health are essential to mitigate this risk.

Overall, RAID configurations in NAS TerraMaster U8-420 devices can significantly reduce the risk of data loss by providing redundancy, data protection, and hot-swapping capabilities. However, it is important to regularly monitor the array's health, promptly replace failed disks, and maintain backups to ensure data integrity and minimize the impact of potential failures.

How to take hard disks out of the NAS and connect them to a PC?

Although NAS U8-420 can be accessed over the network, you still need to take the hard disks out of the storage device and connect them to a Windows computer. Only in this case will the software be able to scan them properly. Here is what you should do:

1. Turn off the storage and disconnect it from the power supply.

   WARNING! Before you start taking hard disks out of your NAS device, read the manual carefully. Incorrect actions may damage your network-attached storage and/or the hard disks within the RAID system.

2. Take the hard disks out of the NAS one by one, carefully removing them from their slots. Remember that the disks are extremely vulnerable: hitting or dropping them may result in serious physical damage.

3. Make sure to mark each hard disk in accordance with how they were installed inside the NAS.

4. Remove the hard disks and connect them to the computer. In this video, we have explored what ports are used to connect hard disks, and what to do if there are not enough ports or connectors.

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   How to Order Remote Data Recovery

Restoring data with Hetman RAID Recovery

This program recovers data from damaged RAID arrays and is fully compatible with TerraMaster U8-420. The hard disks that make up the RAID contain technical information about the algorithm used to save files. When launched, Hetman RAID Recovery reads this information and puts the damaged array together. Then you can open the disk and save your files. Also, you can recover the files accidentally deleted from the network drive.

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How to recover data from a TerraMaster

U8-420 has 8 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;

Safe recovery from disk images

This utility lets you save an entire copy of the disk to file and then work with this image instead of the actual disk. Such feature helps to protect data on the disk from:

• Overwriting during the recovery process;
• Loss resulting from bad sectors;
• User mistakes.

To create an image, do the following:

1. Make sure that you have enough free space to save the image. The image file size usually equals the disk size.

2. Select the disk in the main window, and choose from the menu Tools – Save Disk. You can select multiple disks to be saved.

3. When the image creation wizard starts, you can choose to save the entire disk or select only a part of it. Specify the parameters and click Next.

   

4. At this stage, you need to choose a directory where to save the image. Choose any disk connected to this PC, or save the image by FTP.

   

Where are user’s files stored?

The TerraMaster U8-420 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.

Comparison of software for RAID recovery