- 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.
Are there any known limitations or performance issues related to specific RAID levels in NAS QNAP VS-4012 Pro devices?
There are some limitations and performance issues related to specific RAID levels in QNAP VS-4012 Pro devices. Here are a few examples:
- RAID 5 and RAID 6: These RAID levels provide data redundancy by distributing parity information across multiple drives. However, the write performance can be slower compared to other RAID levels due to the need to calculate and write parity information.
- RAID 0: This RAID level offers improved performance by striping data across multiple drives without any redundancy. However, it does not provide any data protection. If one drive fails, all data stored on the RAID 0 array may be lost.
- RAID 10: This RAID level combines the benefits of RAID 1 (data mirroring) and RAID 0 (performance). It offers improved read and write performance as well as data redundancy. However, it requires a larger number of drives compared to other RAID levels, which can increase the cost.
- RAID Expansion: When expanding a RAID array by adding more drives, the process can take a significant amount of time, especially for larger arrays. During the expansion process, the performance of the NAS device may be affected.
- Rebuilding RAID: When a drive fails in a RAID array, the NAS device needs to rebuild the data on the replacement drive. This process can also take a considerable amount of time, during which the performance of the NAS may be reduced.
It's important to note that the performance and limitations can vary depending on the specific model of the QNAP VS-4012 Pro device and the configuration of the RAID array. It's recommended to consult the product documentation or contact QNAP support for more detailed information about the specific limitations and performance considerations for your device.
How to take hard disks out of the NAS and connect them to a PC?
Although NAS VS-4012 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-4012 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-4012 Pro has 4 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:
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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-4012 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 |
Yes, data recovery from a NAS QNAP VS-4012 Pro device can still be possible even if there are issues with the operating system or firmware. In such cases, the data recovery process usually involves removing the hard drives from the QNAP device and connecting them to a computer or another NAS device. Specialized data recovery software or services can then be used to scan and recover the data from the drives. It is important to note that attempting data recovery on your own may carry risks, so it is recommended to consult with professional data recovery services for the best chance of success.