Avoiding Data Loss on NAS D-Link DNS-345 and Recovering Deleted Files: Strategic Tips

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 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.

Are there any known limitations or issues related to specific NAS D-Link DNS-345 device models that can lead to data loss?

Yes, there have been reported limitations and issues related to the D-Link DNS-345 device models that can potentially lead to data loss. Some of the known limitations and issues include:

1. Firmware bugs: Certain firmware versions of the DNS-345 have been known to have bugs that can cause data loss. It is recommended to keep the firmware up to date to avoid such issues.
2. Drive compatibility: Some users have reported compatibility issues with certain hard drive models, leading to data corruption or loss. It is advisable to check the compatibility list provided by D-Link and use compatible drives to minimize the risk.
3. RAID rebuild failures: During the process of rebuilding a RAID array, there have been instances where the DNS-345 fails to rebuild properly, resulting in data loss. It is recommended to have proper backups in place before attempting any RAID rebuild.
4. Power supply failures: In some cases, the power supply unit of the DNS-345 has failed, leading to unexpected shutdowns and potential data loss. Using a reliable power source and regularly checking the health of the power supply can help mitigate this risk.
5. Lack of data redundancy: The DNS-345 does not support certain RAID configurations like RAID 5 or RAID 6, which provide data redundancy. This means that if a drive fails, there is no automatic data recovery, increasing the risk of data loss.

It is important to note that these issues may not be widespread, and many users have successfully used the D-Link DNS-345 without experiencing data loss. However, it is always recommended to have proper backups and take necessary precautions to safeguard your data.

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

Although NAS DNS-345 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 D-Link DNS-345. 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 D-Link

DNS-345 has 4 HDD slots, and it supports the following array types:

• RAID 0;
• RAID 1;
• RAID 5;
• RAID 6;
• RAID 10;
• 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:

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 D-Link DNS-345 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