NAS Synology DiskStation DS211+ / DS211 / DS211j RAID Arrays: Data Recovery Steps for Handling 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.

How can file system corruption impact data integrity on NAS Synology DiskStation DS211+ / DS211 / DS211j devices?

File system corruption can have several impacts on data integrity on NAS Synology DiskStation DS211+ / DS211 / DS211j devices:

1. Data Loss: File system corruption can lead to the loss of data stored on the NAS device. This can happen if the corruption affects critical system files or if the corruption prevents proper access to the stored data.
2. Inaccessibility: Corrupted file systems can make it difficult or impossible to access the data stored on the NAS device. This can result in the loss of important files and documents.
3. Data Corruption: File system corruption can also lead to data corruption, where the stored files become unreadable or contain errors. This can render the data useless or result in the loss of important information.
4. Unreliable backups: NAS devices often provide backup functionality, allowing users to create backups of their data. However, if the file system on the NAS device is corrupted, the backups may also be affected, rendering them unreliable or useless.
5. System Instability: File system corruption can cause the NAS device to become unstable, leading to frequent system crashes, freezes, or other performance issues. This can further impact the integrity of the data stored on the device.

To mitigate the impact of file system corruption on data integrity, it is recommended to:

1. Regularly backup data: Implement a regular backup strategy to ensure that important data is stored in multiple locations, reducing the risk of complete data loss.
2. Use RAID or redundancy: Employ RAID (Redundant Array of Independent Disks) or other redundancy mechanisms to protect against data loss in case of file system corruption or hardware failures.
3. Implement data integrity checks: Enable data integrity checks, such as periodic filesystem scans or checksum verification, to detect and correct any file system corruption issues early on.
4. Keep the NAS firmware up to date: Regularly update the NAS firmware to ensure that any known file system corruption issues are addressed by the manufacturer.
5. Monitor and maintain the NAS device: Regularly monitor the NAS device for any signs of file system corruption or degradation and promptly address any issues that arise.

By following these measures, you can minimize the impact of file system corruption on data integrity on NAS Synology DiskStation DS211+ / DS211 / DS211j devices.

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

Although NAS DiskStation DS211+ / DS211 / DS211j 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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   How to Order Remote Data Recovery

Restoring data with Hetman RAID Recovery

This program recovers data from damaged RAID arrays and is fully compatible with Synology DiskStation DS211+ / DS211 / DS211j. 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 DS211+ / DS211 / DS211j has 2 HDD slots, and it supports the following array types:

• Synology Hybrid RAID;
• RAID 1;
• RAID 0;
• Basic;
• JBOD;

NAS supports:

• EXT4;
• EXT3;
• FAT32 (External Disk Only);
• NTFS (External Disk Only);

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 DS211+ / DS211 / DS211j network-attached storage keeps DSM (DiskStation Manager) 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