RAID Array Recovery on NAS Thecus N5500: Best Practices for Recovery When It Breaks

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 specific network security measures to implement for safeguarding NAS Thecus N5500 devices against data loss?

Yes, there are several network security measures that you can implement to safeguard NAS Thecus N5500 devices against data loss. Here are a few important ones:

1. Secure Network Configuration: Ensure that your NAS device is connected to a secure network and configure proper firewall rules to restrict unauthorized access.
2. Strong User Authentication: Enforce strong passwords for all user accounts and enable two-factor authentication if available. Regularly review and update user access permissions.
3. Regular Firmware Updates: Keep the firmware of your NAS device up to date with the latest security patches and bug fixes. This helps protect against known vulnerabilities.
4. Data Encryption: Enable encryption for sensitive data stored on the NAS device. This ensures that even if the device is compromised, the data remains protected.
5. Backup and Disaster Recovery: Implement a regular backup strategy to ensure that data is regularly backed up to an off-site location. This helps in recovering data in case of device failure or data loss.
6. Access Control: Configure access control lists (ACLs) to restrict access to the NAS device based on IP addresses, user groups, or specific users. Only allow necessary access to minimize the attack surface.
7. Intrusion Detection and Prevention: Enable intrusion detection and prevention systems (IDPS) to monitor network traffic and detect any suspicious activity. This helps in identifying and mitigating potential threats.
8. Antivirus and Malware Protection: Install and regularly update antivirus and anti-malware software on the NAS device. This helps in detecting and removing any malicious software that could compromise data.
9. Physical Security: Ensure that the NAS device is physically secured in a locked room or cabinet, limiting physical access to authorized personnel only.
10. Regular Monitoring and Auditing: Monitor the NAS device logs regularly for any suspicious activity. Implement an auditing system to track and review any changes made to the device's configuration or data.

Implementing these network security measures will significantly enhance the protection of your NAS Thecus N5500 devices against data loss.

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

Although NAS N5500 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 N5500. 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

N5500 has 5 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 N5500 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