- 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 VS-8148U-RP Pro devices?
Regular data verification or checksum processes can help maintain data integrity on NAS QNAP VS-8148U-RP Pro devices in the following ways:
- Detecting Data Corruption: Data verification processes involve comparing the checksums of files or data blocks with their expected values. If the checksums do not match, it indicates that the data has been corrupted. Regular verification helps identify corrupted data early on, allowing for prompt action to restore or replace the affected files.
- Preventing Silent Data Corruption: Silent data corruption refers to errors that occur during data storage or transmission without being detected by the system. By regularly running checksum processes, you can identify silent data corruption and take corrective measures before it leads to significant data loss or system failures.
- Ensuring Data Integrity during Transfer: When transferring data to or from the NAS device, checksum processes can verify the integrity of the transferred data. By comparing the checksums before and after the transfer, you can ensure that the data has been successfully and accurately transferred without any corruption or modification.
- Early Detection of Hardware Issues: Regular data verification can also help identify potential hardware issues within the NAS device. If checksum mismatches occur frequently or consistently, it may indicate problems with the storage media, memory, or other components. Identifying these issues early can help prevent data loss and allow for timely repairs or replacements.
- Maintaining Data Consistency: By regularly verifying the integrity of data stored on the NAS device, you can ensure that it remains consistent over time. This is particularly important in environments where multiple users or applications access and modify the data. Regular verification helps identify any inconsistencies or discrepancies that may arise due to accidental or unauthorized modifications.
Overall, regular data verification or checksum processes provide an additional layer of protection against data corruption, silent errors, and hardware issues. By incorporating these processes into your data management practices, you can enhance the reliability and integrity of your data on QNAP VS-8148U-RP Pro devices.
How to take hard disks out of the NAS and connect them to a PC?
Although NAS VS-8148U-RP Pro 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 VS-8148U-RP Pro. 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.
VS-8148U-RP Pro 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 VS-8148U-RP 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.
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 |
To make a backup for your QNAP VS-8148U-RP Pro NAS, you can follow these steps:
It is recommended to periodically check the backup status, update the backup settings, and test the restore process to ensure the backup's reliability.