
- Why Regular Data Recovery Tools Can’t Restore Files from RAID
- Key Information About the NAS QNAP TVS-672N
- How to Remove Hard Disks from Your NAS and Connect Them to a PC
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 TVS-672N devices?
Regular disk health monitoring and analysis can help in preventing potential data loss on NAS QNAP TVS-672N devices in the following ways:
- Early detection of disk failures: By monitoring the health of individual disks in the NAS device, you can identify any signs of potential failures or issues. This allows you to take proactive measures such as replacing the failing disk before it completely fails and causes data loss.
- RAID array maintenance: QNAP TVS-672N devices often use RAID configurations for data redundancy and protection. Regular disk health monitoring helps in identifying any degraded or failed disks within the RAID array. By replacing the failed disk and rebuilding the array promptly, you can prevent data loss.
- SMART monitoring: SMART (Self-Monitoring, Analysis, and Reporting Technology) is a feature available in most modern hard drives. It constantly monitors various parameters of the disk, such as temperature, bad sectors, and read/write errors. By regularly analyzing the SMART data, you can anticipate potential disk failures and take necessary actions to prevent data loss.
- Disk usage and capacity planning: Monitoring disk health also involves tracking disk usage and capacity. By analyzing the usage patterns and available capacity, you can plan for future storage requirements and ensure that your NAS device doesn't run out of space unexpectedly. This helps in preventing data loss due to insufficient storage.
- Data backup and replication: Regular disk health monitoring can remind you to regularly back up your data and replicate it to remote locations or cloud storage. This ensures that even if a disk fails or data loss occurs, you have a recent backup to restore from.
- Firmware and software updates: Disk health monitoring can also alert you to firmware or software updates released by QNAP. Keeping your NAS device up to date with the latest firmware and software patches helps in maintaining the overall health and security of the system, reducing the chances of data loss due to vulnerabilities or bugs.
In summary, regular disk health monitoring and analysis on NAS QNAP TVS-672N devices enable early detection of disk failures, proactive maintenance of RAID arrays, monitoring of SMART data, capacity planning, data backup, and replication, as well as staying up to date with firmware and software updates. All these measures collectively help in preventing potential data loss.
How to Remove Hard Disks from Your NAS and Connect Them to a PC
Although the NAS TVS-672N 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:
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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.
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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.
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Label each hard disk according to its position inside the NAS. The order of the drives is crucial for correct RAID reconstruction.
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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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Step-by-Step Data Recovery with Hetman RAID Recovery

This program restores data from damaged RAID arrays and is fully compatible with QNAP TVS-672N. 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.
How to recover data from a QNAP
TVS-672N has 6 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:
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Ensure you have enough free space to store the image. Its size will typically match the size of the original disk.
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In the main window, select the target disk and choose Tools - Save Disk. You can also select multiple disks if needed.
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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.

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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 TVS-672N 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
| Product | Operating system | RAID controller support | Supported file systems | Virtual RAID controller support | Data recovery from damaged RAID | File preview |
|---|---|---|---|---|---|---|
| Hetman RAID Recovery | Windows, Linux, MacOS | Yes, over 100 controllers | FAT, exFAT, NTFS, ReFS, APFS, HFS+, Ext4, Ext3, Ext2, ReiserFS, Btrfs, VMFS, Hikvision, XFS, UFS, ZFS | Yes | Yes | Yes |
| DiskInternals RAID Recovery | Windows | Yes, over 10 controllers | FAT, NTFS, Ext2/3/4, HFS+ | No | Yes | Yes |
| R-Studio | Windows, Mac, Linux | Yes, over 20 controllers | FAT, NTFS, Ext2/3/4, HFS+ | Yes | Yes | Yes |
| UFS Explorer RAID Recovery | Windows, Mac, Linux | Yes, over 100 controllers | FAT, NTFS, Ext2/3/4, HFS+ | Yes | Yes | Yes |
| EaseUS Data Recovery | Windows | Yes, over 20 controllers | FAT, NTFS, Ext2/3/4, HFS+ | No | Yes | Yes |
| ReclaiMe Free RAID Recovery | Windows | Yes, over 100 controllers | FAT, NTFS, Ext2/3/4, HFS+ | Yes | Yes | Yes |


Yes, there are some precautions that need to be taken while attempting data recovery from a NAS QNAP TVS-672N device. Here are some important points to consider:
Remember, data recovery from a NAS device can be complex and delicate. It is always better to seek professional help to maximize the chances of successful recovery without further damage to the data or device.