NAS Synology DiskStation DS1522+ RAID Arrays: Data Recovery After Natural Component Deterioration

Contents

• Why Regular Data Recovery Tools Can’t Restore Files from RAID
• Key Information About the NAS Synology DiskStation DS1522+
• 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 data fragmentation impact data availability and potential loss on NAS Synology DiskStation DS1522+ devices?

Data fragmentation can impact data availability and potential loss on NAS Synology DiskStation DS1522+ devices in the following ways:

1. Reduced performance: Fragmentation causes files to be scattered across different physical locations on the hard drive, resulting in slower read and write speeds. This can affect the responsiveness of the NAS device and lead to reduced performance when accessing or transferring data.
2. Increased disk wear: Fragmentation can cause the hard drive to work harder to retrieve the scattered data, leading to increased wear and tear on the disk. This can potentially shorten the lifespan of the hard drive and increase the risk of data loss due to hardware failure.
3. Higher risk of data loss: Fragmentation can increase the likelihood of data loss in several ways. Firstly, if a fragmented file is partially overwritten or corrupted, it becomes more difficult to recover the complete file. Secondly, if the file system metadata becomes fragmented, it can result in file system errors or even complete data loss. Lastly, if the fragmented data is not properly backed up, any data loss or corruption can be irreversible.
4. Difficult data recovery: In the event of data loss or corruption, fragmented data can be more challenging to recover. Fragmented files may require specialized data recovery tools or techniques to retrieve the scattered data blocks and reconstruct the complete file. This can increase the complexity and time required for data recovery, potentially impacting data availability.

To mitigate these risks, it is important to regularly defragment the hard drives on NAS Synology DiskStation DS1522+ devices. Defragmentation rearranges the fragmented data blocks, improving performance, reducing disk wear, and lowering the risk of data loss. Additionally, implementing a robust backup strategy, including regular backups and offsite storage, can help protect against data loss in case of hardware failure or other issues.

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

Although the NAS DiskStation DS1522+ 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 DS1522+. 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 DS1522+ has 5 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 DiskStation DS1522+ 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