Avoiding Data Loss on NAS Thecus N4560 and Recovering Deleted Files: Insider Techniques

Contents

• Why Regular Data Recovery Tools Can’t Restore Files from RAID
• Key Information About the NAS Thecus N4560
• 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 Thecus 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 quality of service (QoS) settings impact data transfer reliability on NAS Thecus N4560 devices?

Quality of Service (QoS) settings can have a significant impact on data transfer reliability on NAS Thecus N4560 devices. Here are a few ways QoS settings can affect data transfer reliability:

1. Bandwidth Allocation: QoS settings allow you to allocate bandwidth to different applications or services on your NAS. By prioritizing certain applications, such as file transfers, over others, you can ensure that data transfers receive sufficient bandwidth for reliable and uninterrupted transfers.
2. Traffic Prioritization: QoS settings enable you to prioritize specific types of traffic, such as FTP or SMB, over others. By giving higher priority to data transfer protocols, you can ensure that file transfers are not affected by other network activities, such as streaming or web browsing, which may consume bandwidth and cause interruptions.
3. Traffic Shaping: QoS settings also allow you to shape the traffic flow by setting limits on the maximum upload and download speeds for different applications or services. By properly configuring traffic shaping, you can prevent any single application from consuming excessive bandwidth, which can lead to dropped packets and reduced reliability during data transfers.
4. Buffer Management: QoS settings can help manage buffer sizes and buffer thresholds on the NAS device. By optimizing buffer settings, you can reduce latency and ensure a smooth and reliable data transfer experience. Proper buffer management can prevent issues like packet loss or delays, which can impact the reliability of data transfers.
5. Congestion Control: QoS settings help in managing network congestion by preventing network saturation. By setting appropriate congestion control mechanisms, such as traffic prioritization or traffic shaping, you can avoid network congestion, which can lead to packet loss and reduced reliability during data transfers.

It is important to note that configuring QoS settings requires a good understanding of your network environment and the specific requirements of your data transfers. Properly configuring QoS settings on Thecus N4560 devices can significantly enhance data transfer reliability and ensure a smooth and uninterrupted experience.

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

Although the NAS N4560 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 Thecus N4560. 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 Thecus

N4560 has 4 HDD slots, and it supports the following array types:

• RAID 0;
• RAID 1;
• RAID 5;
• RAID 6;
• RAID 10;
• JBOD;

NAS supports:

• EXT3;
• EXT4;
• XFS;

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 Thecus N4560 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