Avoiding Data Loss on NAS Thecus N2520 and Recovering Deleted Files: Complete Plan

Contents

• Why Regular Data Recovery Tools Can’t Restore Files from RAID
• Key Information About the NAS Thecus N2520
• 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 data fragmentation impact the read and write speeds, and potential data loss on NAS Thecus N2520 devices?

Data fragmentation can have several impacts on read and write speeds, as well as potential data loss, on NAS Thecus N2520 devices:

1. Read and Write Speeds: When data is fragmented, it is scattered across different physical locations on the storage device. This can lead to slower read and write speeds as the device needs to access multiple locations to retrieve or store the fragmented data. The fragmented data may also result in increased seek times, which further slows down the read and write operations.
2. Disk Fragmentation: Data fragmentation can also lead to disk fragmentation, where files are stored in non-contiguous clusters on the disk. This can cause additional delays in accessing the data, as the disk heads need to move to different locations to read or write the fragmented files.
3. Data Loss: Fragmented data can increase the risk of data loss. If a file is fragmented and one of the fragments becomes corrupted or lost, it may render the entire file inaccessible. As the NAS device stores data across multiple drives, the chances of data loss increase if the fragmentation is not managed properly.
4. Increased Wear and Tear: Fragmentation can cause increased wear and tear on the storage device. As the device needs to perform additional read and write operations to access fragmented data, it can lead to increased stress on the drive, potentially reducing its lifespan.

To mitigate these impacts, it is important to regularly defragment the NAS device. Defragmentation rearranges the fragmented data and organizes it in a more contiguous manner, improving read and write speeds and reducing the risk of data loss. Thecus N2520 devices may have built-in defragmentation tools or support third-party defragmentation software that can be used to optimize the storage and reduce fragmentation. Regular backups of important data should also be maintained to mitigate the risk of data loss.

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

Although the NAS N2520 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 N2520. 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

N2520 has 2 HDD slots, and it supports the following array types:

• RAID 0;
• RAID 1;
• 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 N2520 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