NAS Synology Rack Station RS818RP+ / RS818+ RAID Arrays: Data Recovery Techniques Following Component Wear

Contents

• Why Regular Data Recovery Tools Can’t Restore Files from RAID
• Key Information About the NAS Synology Rack Station RS818RP+ / RS818+
• 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 Rack Station RS818RP+ / RS818+ devices?

Data fragmentation can have several impacts on data availability and potential loss on NAS Synology Rack Station RS818RP+ / RS818+ devices:

1. Reduced Performance: Fragmented data requires the NAS device to spend more time searching for and accessing scattered data blocks, resulting in slower read and write speeds. This can lead to reduced overall performance and slower data availability.
2. Increased Disk Wear: Fragmentation can cause excessive disk head movement as the NAS device tries to access scattered data blocks. This increased movement can lead to increased wear and tear on the hard drives, potentially shortening their lifespan and increasing the risk of data loss.
3. Increased Risk of Data Loss: Fragmented data is more susceptible to data loss in case of disk failure. If a fragmented file is spread across multiple disks and one of them fails, it becomes difficult to recover the complete file. This can result in partial or complete data loss, depending on the level of fragmentation.
4. Longer Backup and Restore Times: Fragmented data can significantly increase the time required for backup and restore operations. Backup processes may take longer as the NAS device needs to read scattered data blocks from different areas of the disk. Similarly, restoring fragmented data can be time-consuming as the device needs to locate and reassemble the scattered blocks.
5. Difficulty in Data Recovery: In the event of data corruption or accidental deletion, fragmented data can make data recovery more challenging. The scattered nature of the data makes it harder for data recovery tools to locate and recover the complete files, increasing the risk of permanent data loss.

To mitigate the impact of data fragmentation, it is recommended to regularly defragment the NAS device's hard drives. This process rearranges the fragmented data blocks, optimizing data storage and improving overall performance. Additionally, implementing a proper backup strategy, including off-site backups, can help protect against data loss caused by fragmentation or other issues.

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

Although the NAS Rack Station RS818RP+ / RS818+ 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 RS818RP+ / RS818+. 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 RS818RP+ / RS818+ 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 RS818RP+ / RS818+ 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