Avoiding Data Loss on NAS Thecus N4910U PRO-S/R and Recovering Deleted Files: Step-by-Step Plan

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 Thecus 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 issues or limitations when using NAS Thecus N4910U PRO-S/R devices with virtualization platforms such as VMware or Hyper-V?

There are a few known issues and limitations when using Thecus N4910U PRO-S/R devices with virtualization platforms like VMware or Hyper-V:

1. Limited CPU and Memory Resources: The Thecus N4910U PRO-S/R devices have limited CPU and memory resources compared to dedicated server hardware. This can affect the number and performance of virtual machines (VMs) that can be run simultaneously.
2. Lack of Hardware Virtualization Support: The Thecus N4910U PRO-S/R devices do not have built-in hardware virtualization support, which can impact the performance and capabilities of VMs. However, software virtualization can still be used, but it may be less efficient.
3. Limited Storage Expansion Options: The Thecus N4910U PRO-S/R devices have a limited number of drive bays, which can restrict the amount of storage available for VMs. This can be a limitation if you require a large amount of storage for your virtualization environment.
4. Network Bandwidth Limitations: The network bandwidth of the Thecus N4910U PRO-S/R devices may not be sufficient for high-performance virtualization environments. This can impact the network performance of VMs, especially if multiple VMs are running simultaneously.
5. Limited Support and Compatibility: The Thecus N4910U PRO-S/R devices may have limited support and compatibility with virtualization platforms like VMware or Hyper-V. It is important to check the compatibility list provided by the virtualization platform vendor to ensure that the NAS device is supported.
6. Lack of Advanced Virtualization Features: The Thecus N4910U PRO-S/R devices may not support advanced virtualization features like live migration, high availability, or fault tolerance. These features are typically found in enterprise-grade virtualization platforms and may not be available on NAS devices.

Overall, while the Thecus N4910U PRO-S/R devices can be used with virtualization platforms, they may have limitations and may not be suitable for demanding virtualization environments. It is recommended to carefully evaluate your requirements and consider dedicated server hardware for more robust virtualization deployments.

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

Although NAS N4910U PRO-S/R 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 Thecus N4910U PRO-S/R. 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 Thecus

N4910U PRO-S/R has 4 HDD slots, and it supports the following array types:

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

NAS supports:

• EXT3;
• EXT4;
• XFS;

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 Thecus N4910U PRO-S/R 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