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

Contents

• Why can’t ordinary software tools restore files from RAID?
• How to take hard disks out of the NAS and connect them to a PC?
  • Restoring data with Hetman RAID Recovery
  • Safe recovery from disk images
  • Where are user’s files stored?
  • Comparison of software for RAID recovery

Why can’t ordinary software tools restore files from RAID?

Conventional hard disks keep user’s data by writing it to their surface in a consecutive way, and this is how an entire file is stored on a single hard disk. However, when data is written to a RAID system, a file is divided into several parts. Then these parts are written consecutively to all hard disks within such array. The size of such parts may range from 2 KB to 2 MB, so each file is stored on several hard disks at the same time.

Such approach helps to speed up read and write operations, and it is evident that saving two parts of a file having the size of 1 GB to two hard disks simultaneously is much faster than saving the same 1 GB of data to one hard disk. However, this peculiarity makes file recovery more complicated.

Various RAID levels store information in different ways. Additionally, manufacturers like Synology also introduce some modifications to this process, and that is why data can be written to hard disk in a wide variety of ways.

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 take hard disks out of the NAS and connect them to a PC?

Although NAS Diskstation DS920 can be accessed over the network, you still need to take the hard disks out of the storage device and connect them to a Windows computer. Only in this case will the software be able to scan them properly. Here is what you should do:

1. Turn off the storage and disconnect it from the power supply.

   WARNING! Before you start taking hard disks out of your NAS device, read the manual carefully. Incorrect actions may damage your network-attached storage and/or the hard disks within the RAID system.

2. Take the hard disks out of the NAS one by one, carefully removing them from their slots. Remember that the disks are extremely vulnerable: hitting or dropping them may result in serious physical damage.

3. Make sure to mark each hard disk in accordance with how they were installed inside the NAS.

4. Remove the hard disks and connect them to the computer. In this video, we have explored what ports are used to connect hard disks, and what to do if there are not enough ports or connectors.

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Restoring data with Hetman RAID Recovery

This program recovers data from damaged RAID arrays and is fully compatible with Synology Diskstation DS920. The hard disks that make up the RAID contain technical information about the algorithm used to save files. When launched, Hetman RAID Recovery reads this information and puts the damaged array together. Then you can open the disk and save your files. Also, you can recover the files 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

Safe recovery from disk images

This utility lets you save an entire copy of the disk to file and then work with this image instead of the actual disk. Such feature helps to protect data on the disk from:

• Overwriting during the recovery process;
• Loss resulting from bad sectors;
• User mistakes.

To create an image, do the following:

1. Make sure that you have enough free space to save the image. The image file size usually equals the disk size.

2. Select the disk in the main window, and choose from the menu Tools – Save Disk. You can select multiple disks to be saved.

3. When the image creation wizard starts, you can choose to save the entire disk or select only a part of it. Specify the parameters and click Next.

   

4. At this stage, you need to choose a directory where to save the image. Choose any disk connected to this PC, or save the image by FTP.

   

Where are user’s files 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.

Comparison of software for RAID recovery