Recovering Data from NAS Synology Rack Station RS-406 RAID Arrays: Addressing Component Wear Challenges

Contents

• Why Regular Data Recovery Tools Can’t Restore Files from RAID
• Key Information About the NAS Synology Rack Station RS-406
• 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.

How can the number of drives in a NAS Synology Rack Station RS-406 device's RAID array impact data recovery and potential loss?

The number of drives in a NAS Synology Rack Station RS-406 device's RAID array can have an impact on data recovery and potential loss in the following ways:

1. Data redundancy: RAID arrays use various levels (RAID 0, RAID 1, RAID 5, etc.) to provide data redundancy and protection against drive failures. The more drives in the array, the higher the level of redundancy and protection. For example, RAID 5 requires a minimum of three drives, while RAID 6 requires a minimum of four drives. With more drives, the array can withstand multiple drive failures without losing data.
2. Failure rate: As the number of drives in the RAID array increases, so does the probability of drive failures. Each drive in the array has its own failure rate, and the more drives there are, the higher the chances of one or more drives failing simultaneously. This increases the risk of potential data loss.
3. Rebuilding time: When a drive fails in a RAID array, the data needs to be rebuilt onto a replacement drive. The larger the RAID array, the longer it takes to rebuild the data. During this rebuilding process, the remaining drives are under increased stress, which can potentially lead to additional drive failures. If another drive fails during the rebuilding process, it can result in complete data loss.
4. Data recovery: In the event of multiple drive failures or other catastrophic events, data recovery becomes more challenging with larger RAID arrays. The complexity and cost of recovering data from a larger array are higher compared to smaller arrays. It may require specialized expertise and tools to recover the data, and there is a higher chance of partial or complete data loss.

It's important to regularly backup the data on a NAS device, regardless of the number of drives in the RAID array. Backups provide an additional layer of protection and can help mitigate the risks associated with data loss in RAID arrays.

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

Although the NAS Rack Station RS-406 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 Rack Station RS-406. 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

Rack Station RS-406 has 4 HDD slots, and it supports the following array types:

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

NAS supports:

• Btrfs;
• EXT4;
• EXT3 (External Disk Only);
• FAT32 (External Disk Only);
• exFAT (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 Synology Rack Station RS-406 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.

RAID Recovery Software: Detailed Comparison