Best Practices for Recovering Data from NAS Promise Vess A3340 RAID Array Failures

Contents

• Why Regular Data Recovery Tools Can’t Restore Files from RAID
• Key Information About the NAS Promise Vess A3340
• 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 Promise 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 file system corruption impact data integrity on NAS Promise Vess A3340 devices?

File system corruption can have a significant impact on data integrity on NAS Promise Vess A3340 devices. Here are some ways it can affect data integrity:

1. Data loss: File system corruption can lead to the loss of data stored on the NAS device. This can occur due to the inability to access or recover files, or the corruption of file metadata that makes it impossible to locate and retrieve the data.
2. Data inconsistency: File system corruption can cause inconsistencies in the data stored on the NAS device. This means that the data may be incomplete, contain errors, or be in an unexpected state. Inconsistent data can lead to issues like incorrect calculations, inaccurate reports, or improper functioning of applications that rely on the data.
3. Data integrity violations: File system corruption can result in data integrity violations, where the data stored on the NAS device does not meet the expected integrity constraints. This can include issues like duplicate data, invalid references, or data that violates integrity rules defined by the file system or applications.
4. Unreliable backups: File system corruption can also impact the reliability of backups taken on the NAS device. If the corruption affects the backup files or the ability to restore them, it can lead to data loss or incomplete recovery in case of a disaster or data corruption event.
5. Performance degradation: File system corruption can cause performance degradation on the NAS device. This can occur due to the need for additional processing and error handling to deal with the corrupted file system, resulting in slower access times and reduced overall performance.

To mitigate the impact of file system corruption on data integrity, it is important to regularly backup data, perform integrity checks, and implement preventive measures such as using reliable hardware, keeping the firmware up to date, and implementing proper security measures to prevent unauthorized access or malicious actions.

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

Although the NAS Vess A3340 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 Promise Vess A3340. 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 Promise

Vess A3340 has 8 HDD slots, and it supports the following array types:

• RAID 0;
• RAID 1;
• RAID 1E;
• RAID 3;
• RAID 5;
• RAID 6;
• RAID 30;
• 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 Promise Vess A3340 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