How to Recover Data from NAS Synology Diskstation DS920 RAID Arrays: Recovery Steps for Component Wear

Contents

• Why Regular Data Recovery Tools Can’t Restore Files from RAID
• Key Information About the NAS Synology Diskstation DS920
• 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 Synology 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.

Are there any recommended steps to take after detecting or suspecting data loss on a NAS Synology Diskstation DS920 device?

If you suspect or detect data loss on a Synology DiskStation DS920 device, here are some recommended steps to take:

1. Stop all disk-related activities: Once you notice data loss, it is crucial to stop all disk-related activities on the NAS immediately. This includes disabling any services or applications that may be accessing the disks.
2. Check the status of the disks: Log in to the Synology DiskStation Manager (DSM) web interface and navigate to the Storage Manager. Check the status of the disks to ensure they are healthy and functioning properly.
3. Verify connectivity and power: Ensure that all cables connecting the NAS to the network and power source are secure. Sometimes, data loss can occur due to loose connections or power interruptions.
4. Restart the NAS: Try restarting the NAS to see if it resolves any temporary issues. This can be done through the DSM web interface or by physically powering off and on the device.
5. Run disk checks and repairs: Use the built-in tools provided by Synology to check and repair the disks. DSM offers options such as "Check File System" and "Repair" within the Storage Manager. These tools can help identify and fix any file system errors.
6. Restore from backups: If you have regular backups of your data, restore the lost files from the backup source. Synology DiskStation devices offer various backup options like Hyper Backup, Time Machine, or third-party backup applications.
7. Contact Synology support: If the above steps do not resolve the data loss issue, it is recommended to contact Synology support for further assistance. They can provide guidance specific to your device and help you recover your data.

Remember, it is important to have regular backups of your data to minimize the impact of data loss. Regularly check the health of your disks and perform routine maintenance to prevent data loss incidents.

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

Although the NAS Diskstation DS920 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 Synology Diskstation DS920. 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 Synology

Diskstation DS920 has 4 HDD slots, and it supports the following array types:

• Synology Hybrid RAID;
• Basic;
• JBOD;
• RAID 0;
• RAID 1;
• RAID 5;
• RAID 6;
• RAID 10;

NAS supports:

• NTFS

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 Synology Diskstation DS920 network-attached storage keeps DSM 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