- 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?
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 regular data verification or checksum processes help maintain data integrity on NAS QNAP TVS-872XU-RP devices?
Regular data verification or checksum processes can help maintain data integrity on NAS QNAP TVS-872XU-RP devices in the following ways:
- Detecting Data Corruption: Regular data verification processes involve checking the integrity of the stored data by comparing it against a calculated checksum value. By periodically running data verification checks, any data corruption or errors can be detected. This ensures that the data stored on the NAS device remains intact and has not been altered or corrupted.
- Preventing Silent Data Corruption: Silent data corruption refers to the situation where data gets corrupted without any immediate indication or error message. Regular data verification processes can help identify such silent data corruption by comparing the stored data with the checksum value. If the checksum does not match, it indicates that the data has been corrupted, allowing for timely action to restore the data from backups or other measures.
- Early Detection of Hardware Issues: Data verification processes not only check the integrity of the stored data but also verify the health of the underlying hardware components. If errors are detected during the verification process, it may indicate potential hardware issues like faulty hard drives or memory modules. Identifying these issues early on can prevent further data corruption and allow for timely hardware maintenance or replacement.
- Ensuring Data Consistency: By regularly running data verification or checksum processes, data consistency can be ensured across different copies or backups of the data. If inconsistencies are detected, it indicates that one or more copies of the data have been corrupted or modified. This allows for taking corrective actions like restoring the data from a known good backup or identifying the cause of inconsistency and rectifying it.
- Maintaining Data Reliability: Data integrity is crucial for maintaining the reliability of the stored data. By regularly verifying the data using checksum processes, the NAS device can ensure that the data remains reliable and trustworthy. This is particularly important for critical data or sensitive information where any corruption or alteration can have significant consequences.
Overall, regular data verification or checksum processes on NAS QNAP TVS-872XU-RP devices can help in maintaining data integrity, preventing data corruption, detecting hardware issues, ensuring data consistency, and maintaining data reliability.
How to take hard disks out of the NAS and connect them to a PC?
Although NAS TVS-872XU-RP 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:
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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.
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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.
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Make sure to mark each hard disk in accordance with how they were installed inside the NAS.
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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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Restoring data with Hetman RAID Recovery
This program recovers data from damaged RAID arrays and is fully compatible with QNAP TVS-872XU-RP. 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.
How to recover data from a QNAP
TVS-872XU-RP has 8 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);
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:
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Make sure that you have enough free space to save the image. The image file size usually equals the disk size.
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Select the disk in the main window, and choose from the menu Tools – Save Disk. You can select multiple disks to be saved.
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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.
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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-872XU-RP 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
| Product | Operating system | License type | RAID controller support | Supported file systems | Virtual RAID controller support | Data recovery from damaged RAID | File preview |
|---|---|---|---|---|---|---|---|
| Hetman RAID Recovery | Windows | Paid | Yes, over 100 controllers | FAT, NTFS, Ext2/3/4, HFS+ | Yes | Yes | Yes |
| DiskInternals RAID Recovery | Windows | Paid | Yes, over 100 controllers | FAT, NTFS, Ext2/3/4, HFS+ | No | Yes | Yes |
| R-Studio | Windows, Mac, Linux | Paid | Yes, over 200 controllers | FAT, NTFS, Ext2/3/4, HFS+ | Yes | Yes | Yes |
| UFS Explorer RAID Recovery | Windows, Mac, Linux | Paid | Yes, over 1,000 controllers | FAT, NTFS, Ext2/3/4, HFS+ | Yes | Yes | Yes |
| EaseUS Data Recovery | Windows | Paid | Yes, over 20 controllers | FAT, NTFS, Ext2/3/4, HFS+ | No | Yes | Yes |
| ReclaiMe Free RAID Recovery | Windows | Free | Yes, over 100 controllers | FAT, NTFS, Ext2/3/4, HFS+ | Yes | Yes | Yes |
If the disks of a QNAP TVS-872XU-RP NAS device have been reformatted, data recovery becomes more challenging but not impossible. Reformatting erases the file system metadata, making it difficult for the operating system to locate and access the data. However, the actual data might still be present on the disks until overwritten by new data.
To recover data from reformatted disks on a QNAP NAS device, you can try the following steps:
Remember, the success of data recovery depends on various factors, such as the extent of disk usage after reformatting and the effectiveness of the recovery software or service.