NAS QNAP SS-439 Pro RAID Arrays: Recognizing and Recovering from Mechanical and Logical Failures

Contents

• Why Regular Data Recovery Tools Can’t Restore Files from RAID
• Key Information About the NAS QNAP SS-439 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 QNAP 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 continuous data protection mechanisms help in minimizing potential data loss on NAS QNAP SS-439 Pro devices?

Continuous data protection (CDP) mechanisms can help minimize potential data loss on NAS QNAP SS-439 Pro devices in the following ways:

1. Real-time data replication: CDP mechanisms continuously replicate data in real-time to a secondary storage device or location. This ensures that any changes made to the data are immediately replicated, reducing the risk of data loss in case of hardware failures or disasters.
2. Point-in-time recovery: CDP allows for point-in-time recovery, meaning you can restore data to a specific point in time. This is useful in scenarios where data becomes corrupted or accidentally deleted. Instead of relying on traditional backups, CDP allows you to restore the data as it existed at the desired point in time, minimizing data loss.
3. Automatic backup and versioning: CDP mechanisms automatically create backups of data at regular intervals or whenever changes are made. These backups are typically stored separately from the primary storage, reducing the risk of data loss due to hardware failures or malware attacks. Additionally, CDP often supports versioning, allowing you to restore previous versions of files or folders.
4. Continuous monitoring and alerts: CDP solutions continuously monitor the NAS device for any potential issues or anomalies. If any problems are detected, such as disk failures or network connectivity issues, alerts are triggered, allowing administrators to take immediate action to prevent data loss.
5. Rapid recovery: In the event of a data loss incident, CDP mechanisms enable rapid recovery. Since the data is continuously replicated, the recovery process can be initiated quickly, minimizing downtime and reducing the impact on business operations.

Overall, CDP mechanisms provide a proactive approach to data protection, ensuring that data is continuously backed up and readily available for recovery. By minimizing the time between data changes and its replication, CDP helps to minimize potential data loss on NAS QNAP SS-439 Pro devices.

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

Although the NAS SS-439 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 QNAP SS-439 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 QNAP

SS-439 Pro has 4 HDD slots, and it supports the following array types:

• RAID 6;
• RAID 5;
• RAID 10;
• RAID 0;
• RAID 1;
• JBOD;

NAS supports:

• ZFS;
• EXT4;
• EXT3;
• exFAT;
• 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 QNAP SS-439 Pro network-attached storage keeps QTS (QuTS hero) 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