How to recover data from QNAP TVS-682T NAS

Contents

• Why can’t ordinary software tools restore files from RAID?
• How to take hard disks out of the NAS and connect them to a PC?
  • Restoring data with Hetman RAID Recovery
  • Safe recovery from disk images
  • Where are user’s files stored?
  • Comparison of software for RAID recovery

Why can’t ordinary software tools restore files from RAID?

Conventional hard disks keep user’s data by writing it to their surface in a consecutive way, and this is how an entire file is stored on a single hard disk. However, when data is written to a RAID system, a file is divided into several parts. Then these parts are written consecutively to all hard disks within such array. The size of such parts may range from 2 KB to 2 MB, so each file is stored on several hard disks at the same time.

Such approach helps to speed up read and write operations, and it is evident that saving two parts of a file having the size of 1 GB to two hard disks simultaneously is much faster than saving the same 1 GB of data to one hard disk. However, this peculiarity makes file recovery more complicated.

Various RAID levels store information in different ways. Additionally, manufacturers like QNAP also introduce some modifications to this process, and that is why data can be written to hard disk in a wide variety of ways.

How can a NAS QNAP TVS-682T device's caching policy impact data loss risks?

The caching policy of a NAS (Network Attached Storage) device like the QNAP TVS-682T can impact data loss risks in a few ways:

1. Write caching: NAS devices often use write caching to improve performance by temporarily storing data in a fast cache before writing it to the hard drives. However, if there is a power outage or system failure before the data is written from the cache to the drives, there is a risk of data loss. To mitigate this risk, many NAS devices, including the QNAP TVS-682T, provide options to enable write cache flushing or use battery backup units (BBUs) to protect the cached data during power failures.
2. Read caching: NAS devices also utilize read caching to improve read performance by storing frequently accessed data in a cache for faster retrieval. However, if the cached data becomes corrupted or lost, there is a risk of data loss. It is important to regularly monitor the health of the cache and ensure proper backup and redundancy measures are in place to minimize the impact of cache failures.
3. RAID configuration: The TVS-682T supports various RAID configurations to enhance data protection and availability. The choice of RAID level (e.g., RAID 1, RAID 5, RAID 6) can impact data loss risks. For example, RAID 1 provides mirroring, where data is duplicated across multiple drives, offering improved fault tolerance. On the other hand, RAID 5 and RAID 6 provide parity-based protection, allowing for data recovery in case of drive failures. However, if multiple drives fail or encounter errors during rebuilds, there is a higher risk of data loss.
4. Backup and redundancy: Regardless of the caching policy, it is crucial to have proper backup and redundancy strategies in place to mitigate data loss risks. Regularly backing up important data to external storage devices, cloud services, or remote NAS devices can protect against various failure scenarios, including cache failures or multiple drive failures.

Overall, understanding the caching policy of a NAS device like the QNAP TVS-682T and implementing appropriate backup and redundancy measures are essential to minimize data loss risks and ensure data integrity and availability.

How to take hard disks out of the NAS and connect them to a PC?

Although NAS TVS-682T can be accessed over the network, you still need to take the hard disks out of the storage device and connect them to a Windows computer. Only in this case will the software be able to scan them properly. Here is what you should do:

1. Turn off the storage and disconnect it from the power supply.

   WARNING! Before you start taking hard disks out of your NAS device, read the manual carefully. Incorrect actions may damage your network-attached storage and/or the hard disks within the RAID system.

2. Take the hard disks out of the NAS one by one, carefully removing them from their slots. Remember that the disks are extremely vulnerable: hitting or dropping them may result in serious physical damage.

3. Make sure to mark each hard disk in accordance with how they were installed inside the NAS.

4. Remove the hard disks and connect them to the computer. In this video, we have explored what ports are used to connect hard disks, and what to do if there are not enough ports or connectors.

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   How to Order Remote Data Recovery

Restoring data with Hetman RAID Recovery

This program recovers data from damaged RAID arrays and is fully compatible with QNAP TVS-682T. The hard disks that make up the RAID contain technical information about the algorithm used to save files. When launched, Hetman RAID Recovery reads this information and puts the damaged array together. Then you can open the disk and save your files. Also, you can recover the files accidentally deleted from the network drive.

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How to recover data from a QNAP

TVS-682T 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);

Safe recovery from disk images

This utility lets you save an entire copy of the disk to file and then work with this image instead of the actual disk. Such feature helps to protect data on the disk from:

• Overwriting during the recovery process;
• Loss resulting from bad sectors;
• User mistakes.

To create an image, do the following:

1. Make sure that you have enough free space to save the image. The image file size usually equals the disk size.

2. Select the disk in the main window, and choose from the menu Tools – Save Disk. You can select multiple disks to be saved.

3. When the image creation wizard starts, you can choose to save the entire disk or select only a part of it. Specify the parameters and click Next.

   

4. At this stage, you need to choose a directory where to save the image. Choose any disk connected to this PC, or save the image by FTP.

   

Where are user’s files stored?

The QNAP TVS-682T 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.

Comparison of software for RAID recovery