Steps to Recover Your NAS QNAP ES1640dc v2 RAID Array: Steps to Recovery When It Breaks

Contents

• Why Regular Data Recovery Tools Can’t Restore Files from RAID
• Key Information About the NAS QNAP ES1640dc v2
• 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 the number of drives in a NAS QNAP ES1640dc v2 device's RAID array impact data recovery and potential loss?

The number of drives in a NAS QNAP ES1640dc v2 device's RAID array can impact data recovery and potential loss in the following ways:

1. RAID Level: The number of drives determines the RAID level that can be implemented. Different RAID levels offer varying levels of data redundancy and performance. For example, RAID 5 requires a minimum of three drives, while RAID 6 requires at least four drives. Higher RAID levels provide better fault tolerance and protection against drive failures, reducing the risk of data loss.
2. Data Redundancy: The more drives in the RAID array, the higher the level of data redundancy. Redundancy means that if one or more drives fail, the data can still be accessed and recovered from the remaining drives. With more drives, the RAID array can sustain multiple drive failures without losing data.
3. Rebuild Time: When a drive fails in a RAID array, the data needs to be rebuilt onto a replacement drive. The larger the number of drives in the array, the longer it takes to rebuild the data. During the rebuild process, the array is in a vulnerable state, and if another drive fails, it can lead to data loss. So, a larger number of drives increases the risk of data loss during the rebuild process.
4. Failure Probability: With more drives in a RAID array, the probability of drive failures increases. Each drive has a certain failure rate, and as the number of drives increases, so does the likelihood of encountering a drive failure. If multiple drives fail simultaneously or in close succession, it can result in data loss.
5. Data Recovery Cost: In case of data loss, the cost of data recovery can vary depending on the number of drives in the RAID array. Data recovery from a larger RAID array with more drives can be more complex and expensive compared to a smaller array. This is because the recovery process involves handling multiple drives and reconstructing the data from them.

It is important to carefully consider the number of drives in a NAS QNAP ES1640dc v2 device's RAID array to strike a balance between data redundancy, performance, and the risk of data loss. Regular backups and monitoring the health of the drives can also help mitigate potential data loss risks.

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

Although the NAS ES1640dc v2 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 ES1640dc v2. 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

ES1640dc v2 has 16 HDD slots, and it supports the following array types:

• RAID 50;
• RAID 60;
• RAID 6;
• RAID 5;
• RAID 10;
• RAID 0;
• RAID 1;
• JBOD;

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 ES1640dc v2 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