NAS Digiever DS-16316-RM Pro+ Data Recovery: Best Practices for RAID Array Recovery

Contents

• Why Regular Data Recovery Tools Can’t Restore Files from RAID
• Key Information About the NAS Digiever DS-16316-RM Pro+
• 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 Digiever 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 a NAS Digiever DS-16316-RM Pro+ device's caching policy impact data loss risks?

The caching policy of a NAS (Network Attached Storage) device like the Digiever DS-16316-RM Pro+ can impact data loss risks in the following ways:

1. Write caching: NAS devices often use write caching to improve performance by temporarily storing write operations in cache memory before committing them to the underlying storage disks. While write caching enhances performance, it also introduces a risk of data loss in the event of a power failure or system crash. If the data is only stored in cache and not yet written to the disks, it may be lost. To mitigate this risk, NAS devices typically employ mechanisms like battery backup units (BBUs) or uninterruptible power supplies (UPS) to ensure that cached data is safely written to disk during power failures.
2. Read caching: Read caching is another technique used by NAS devices to accelerate data retrieval. It involves storing frequently accessed data in cache memory, allowing subsequent read requests to be served faster. However, if the cached data becomes corrupted or lost due to a hardware failure or other reasons, there is a risk of data loss. Therefore, it is important to regularly back up the data stored on the NAS device to protect against such potential losses.
3. Cache management: The caching policy and management settings of a NAS device can also impact data loss risks. For example, if the caching policy is set to prioritize performance over data integrity, there may be a higher risk of data loss in case of a system failure. On the other hand, if the caching policy emphasizes data integrity over performance, it may result in slower performance but reduce the risk of data loss. It is crucial to configure the caching policy based on the specific needs and requirements of the data being stored on the NAS device.

Overall, while caching policies can enhance performance, they introduce potential risks of data loss. It is essential to implement appropriate measures like power backup solutions, regular backups, and careful cache management to minimize these risks and ensure data integrity and availability.

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

Although the NAS DS-16316-RM Pro+ 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 Digiever DS-16316-RM Pro+. 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 Digiever

DS-16316-RM Pro+ has 16 HDD slots, and it supports the following array types:

• RAID 0;
• RAID 1;
• RAID 5;
• RAID 6;
• RAID 50;
• RAID 60;
• JBOD;

NAS supports:

• exFAT, VFAT, FAT 12 / 16 / 32;
• NTFS / ReFS;
• APFS / HFS+;
• Ext2 / 3 / 4 / ReiserFS / XFS / UFS / ZFS / Btrfs;
• VMFS / HikvisionFS;

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 Digiever DS-16316-RM Pro+ network-attached storage keeps OS Linux 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