NAS Synology DiskStation DS215+ / DS215j RAID Arrays: Data Recovery Methods After Natural Component Wear

Contents

• Why Regular Data Recovery Tools Can’t Restore Files from RAID
• Key Information About the NAS Synology DiskStation DS215+ / DS215j
• 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.

Are there any specific precautions to take while migrating data between NAS Synology DiskStation DS215+ / DS215j devices?

Yes, there are a few precautions you should take while migrating data between NAS Synology DiskStation DS215+ / DS215j devices. Here are some important steps to follow:

1. Backup your data: Before starting the migration process, it is crucial to create a backup of all your important data. This ensures that even if something goes wrong during the migration, your data remains safe.
2. Check compatibility: Ensure that the Synology DiskStation DS215+ / DS215j devices are compatible with each other for data migration. Check the product specifications and compatibility lists provided by Synology to ensure a smooth migration process.
3. Update firmware: Make sure that both the source and destination DiskStations are running the latest firmware versions. Updating the firmware helps in resolving any known issues and ensures compatibility during the migration process.
4. Plan the migration process: Create a detailed plan for the migration process, including the order of data transfer, any specific settings that need to be configured, and the estimated downtime, if any. This helps in minimizing any potential disruptions during the migration.
5. Use the Data Migration Assistant: Synology provides a Data Migration Assistant tool that simplifies the process of transferring data between DiskStation devices. This tool ensures a smooth and efficient migration process.
6. Test the migration process: Before migrating all your data, it is recommended to perform a test migration with a small amount of data. This helps in identifying any issues or errors that may arise during the migration process and allows you to rectify them before migrating the entire dataset.
7. Monitor the migration: Keep a close eye on the migration process to ensure that it is progressing smoothly. Monitor the transfer speed, any error messages, and the overall progress to identify and resolve any issues promptly.
8. Verify the migrated data: Once the migration is complete, verify the integrity and accessibility of the migrated data. Check if all the files and folders are intact and accessible on the new DiskStation.

By following these precautions, you can minimize the risk of data loss or corruption during the migration process and ensure a successful transfer of data between NAS Synology DiskStation DS215+ / DS215j devices.

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

Although the NAS DiskStation DS215+ / DS215j 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 DS215+ / DS215j. 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 DS215+ / DS215j has 2 HDD slots, and it supports the following array types:

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

NAS supports:

• EXT4;
• EXT3 (External Disk Only);
• FAT32 (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 DS215+ / DS215j 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