NAS QNAP VS-2004L RAID Arrays: Differentiating and Recovering from Mechanical and Logical Failures

Contents

• Why Regular Data Recovery Tools Can’t Restore Files from RAID
• Key Information About the NAS QNAP VS-2004L
• 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 QNAP 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 storage tiering or caching strategies impact data availability and potential loss on NAS QNAP VS-2004L devices?

Storage tiering and caching strategies can greatly impact data availability and potential loss on NAS QNAP VS-2004L devices. Here's how:

1. Improved Data Availability: By implementing storage tiering and caching strategies, you can ensure that frequently accessed data is stored on faster storage tiers or cache, resulting in improved data availability. This means that users can access their data quickly and efficiently, enhancing productivity and reducing downtime.
2. Reduced Potential Data Loss: Storage tiering and caching can also help mitigate potential data loss. By utilizing multiple storage tiers, such as SSDs and HDDs, you can create redundant copies of data, reducing the risk of data loss in case of hardware failures. Additionally, caching can improve data resilience by temporarily storing frequently accessed data in high-speed cache, reducing the reliance on slower storage tiers and minimizing the risk of data loss.
3. Enhanced Performance: Storage tiering and caching strategies can significantly enhance the performance of NAS devices like QNAP VS-2004L. By prioritizing frequently accessed data on faster storage tiers or cache, you can reduce latency and improve read and write speeds. This ensures that users experience faster data access and transfer, resulting in better overall performance.
4. Efficient Resource Utilization: Storage tiering and caching can optimize resource utilization on NAS devices. By intelligently managing data placement across different storage tiers, you can make the most efficient use of available storage capacity. This prevents overutilization of expensive storage tiers and ensures that data is stored on the most appropriate storage medium, reducing costs and maximizing resource utilization.

However, it's important to note that the effectiveness of storage tiering and caching strategies depends on factors such as data access patterns, workload characteristics, and the specific configuration of the NAS device. It's recommended to carefully analyze your data requirements and consult the documentation or support resources provided by QNAP for guidance on implementing storage tiering and caching strategies effectively.

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

Although the NAS VS-2004L 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 QNAP VS-2004L. 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 QNAP

VS-2004L has 2 HDD slots, and it supports the following array types:

• RAID 1;

NAS supports:

• ZFS;
• EXT4;
• EXT3;
• exFAT;
• FAT32 (External Disk Only);
• NTFS (External Disk Only);
• HFS+ (External Disk Read Only);

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 QNAP VS-2004L network-attached storage keeps QTS (QuTS hero) 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