- 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 D-Link 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 hardware failure lead to data loss in NAS D-Link DNS-320 devices?
Hardware failure in NAS D-Link DNS-320 devices can lead to data loss in several ways:
- Disk failure: The most common hardware failure in NAS devices is the failure of hard drives. If one or both of the hard drives in the DNS-320 fail, it can result in data loss. The NAS device may not be able to access the data on the failed drive, and if the data is not backed up elsewhere, it can be permanently lost.
- Power supply failure: If the power supply unit (PSU) of the DNS-320 fails, it can cause the NAS device to shut down abruptly. This sudden power loss can lead to data corruption or loss if the device was in the middle of writing or reading data.
- Controller failure: The controller in the DNS-320 manages the communication between the hard drives and the rest of the system. If the controller fails, it can prevent the NAS device from accessing the data on the hard drives, resulting in data loss.
- Network interface failure: The NAS device relies on its network interface to connect to the network and allow users to access their data remotely. If the network interface fails, it can make the NAS device inaccessible, preventing users from accessing their data.
- Firmware or software corruption: Hardware failures can sometimes cause firmware or software corruption in the NAS device. This can result in the device becoming unresponsive or unable to access the data on the hard drives.
To mitigate the risk of data loss due to hardware failure, it is important to regularly back up the data on the NAS device to an external storage device or cloud storage. Additionally, using RAID (Redundant Array of Independent Disks) configurations such as RAID 1 can provide some level of data redundancy by mirroring the data across multiple hard drives.
How to take hard disks out of the NAS and connect them to a PC?
Although NAS DNS-320 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 D-Link DNS-320. 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 D-Link
DNS-320 has 2 HDD slots, and it supports the following array types:
- RAID 0;
- RAID 1;
- JBOD;
NAS supports:
- exFAT, VFAT, FAT 12 / 16 / 32;
- NTFS / ReFS;
- APFS / HFS+;
- Ext2 / 3 / 4 / ReiserFS / XFS / UFS / ZFS / Btrfs;
- VMFS / HikvisionFS;
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 D-Link DNS-320 network-attached storage keeps OS Linux 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 |
It is possible to recover data from a physically damaged NAS device, but the success of the recovery depends on the extent of the damage. If the power surge only affected the power supply or other internal components, it may be possible to repair or replace those parts and retrieve the data. However, if the damage is extensive, such as to the hard drives or other critical components, the recovery process may be more challenging or even impossible. It is recommended to contact a professional data recovery service for an assessment of the device and to determine the feasibility of data recovery in your specific case.