RAID Array Recovery on NAS QNAP TES-3085U(QTS): How to Handle It When It Fails

Contents

• Why Regular Data Recovery Tools Can’t Restore Files from RAID
• Key Information About the NAS QNAP TES-3085U(QTS)
• 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 regular disk health monitoring and analysis help in preventing potential data loss on NAS QNAP TES-3085U(QTS) devices?

Regular disk health monitoring and analysis can help in preventing potential data loss on NAS QNAP TES-3085U(QTS) devices in the following ways:

1. Early detection of disk failures: Disk health monitoring tools can constantly monitor the SMART (Self-Monitoring, Analysis, and Reporting Technology) data of the disks in the NAS. This allows for the early detection of any signs of disk failure, such as bad sectors, high temperature, or increased error rates. By identifying these issues early on, you can take proactive measures like replacing the failing disk before it completely fails and causes data loss.
2. Predictive failure analysis: Some disk health monitoring tools can analyze the historical SMART data and predict the likelihood of a disk failure in the near future. This allows you to proactively replace the predicted failing disks before they actually fail, minimizing the risk of data loss.
3. RAID array monitoring: If you have set up a RAID configuration on your NAS, disk health monitoring can help in monitoring the status of the RAID array. It can alert you if any disks in the array fail or if there are any issues with the RAID array itself. This allows you to take immediate action to rebuild the array or replace the failed disks, ensuring data integrity and preventing data loss.
4. Temperature monitoring: Overheating can be a common cause of disk failures. Disk health monitoring tools can monitor the temperature of the disks and alert you if they exceed safe operating limits. This allows you to take corrective actions like improving the cooling system or relocating the NAS to a cooler environment, preventing potential data loss due to overheating.
5. Regular data scrubbing: Disk health monitoring tools can also perform regular data scrubbing, which involves reading and verifying the integrity of data stored on the disks. This helps in identifying and correcting any silent data corruption issues before they lead to data loss.
6. Backup monitoring: In addition to disk health monitoring, it is crucial to regularly monitor the status and health of your backup system. This ensures that your backups are up to date, accessible, and in a healthy state, providing an additional layer of protection against data loss.

By regularly monitoring and analyzing the health of the disks in your NAS QNAP TES-3085U(QTS) device, you can proactively identify and address any potential issues that could lead to data loss. This helps in maintaining the reliability and integrity of your data storage system.

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

Although the NAS TES-3085U(QTS) 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 TES-3085U(QTS). 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

TES-3085U(QTS) has 30 HDD slots, and it supports the following array types:

• RAID 50;
• RAID 60;
• 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 TES-3085U(QTS) 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