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

Contents

• Why Regular Data Recovery Tools Can’t Restore Files from RAID
• Key Information About the NAS Thecus N5500
• How to Remove Hard Disks from Your NAS and Connect Them to a PC
  • Step-by-Step Data Recovery with Hetman RAID Recovery
  • How to Safely Recover Data from Disk Images
  • Where Are the User’s Files Actually Stored?
  • RAID Recovery Software: Detailed Comparison

Why Regular Data Recovery Tools Can’t Restore Files from RAID

Conventional hard drives store user data by writing it sequentially across the disk surface, which means an entire file is typically located on a single drive. In contrast, when data is written to a RAID array, each file is split into multiple fragments. These fragments are then distributed and written in sequence across all the drives in the array. Depending on the configuration, fragment sizes can range from 2 KB to 2 MB, so every file is physically stored across several disks at once.

This approach significantly increases read and write performance — after all, writing two halves of a 1 GB file to two drives simultaneously is much faster than writing the full 1 GB to a single disk. However, this same mechanism makes file recovery far more complex.

Different RAID levels use different methods to distribute and protect data. On top of that, manufacturers like Thecus often add their own proprietary structures and variations. As a result, data can be written to disks in many different formats, and each requires a specific approach during recovery.

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 Remove Hard Disks from Your NAS and Connect Them to a PC

Although the NAS N5500 can be accessed over the network, you still need to remove its hard disks and connect them directly to a Windows PC. Only then can the recovery software properly scan and analyze the drives. Follow these steps:

1. Power off the NAS and disconnect it from the power source.

   WARNING! Before removing any drives, carefully read the device manual. Improper actions may damage both the NAS enclosure and the hard disks in the RAID array.

2. Remove the hard disks one by one, gently sliding each drive out of its slot. Remember that hard disks are highly sensitive: any impact or drop can cause serious physical damage.

3. Label each hard disk according to its position inside the NAS. The order of the drives is crucial for correct RAID reconstruction.

4. Connect the drives to your computer. In this video, we explain which ports you can use to connect hard disks and what to do if your PC does not have enough free connectors.

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   How to Order Remote Data Recovery

Step-by-Step Data Recovery with Hetman RAID Recovery

This program restores data from damaged RAID arrays and is fully compatible with Thecus N5500. Each hard disk in the array contains technical metadata describing how files were written. When launched, Hetman RAID Recovery analyzes this metadata, automatically reconstructs the damaged array, and provides access to its contents. After that, you can browse the recovered disk and save your files. The program can also restore files that were 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;

How to Safely Recover Data from Disk Images

This utility allows you to create a complete copy of a disk and work with the disk image instead of the physical drive. This approach helps protect your data from:

• Overwriting during the recovery process;
• Additional data loss caused by bad sectors;
• User errors.

To create a disk image, follow these steps:

1. Ensure you have enough free space to store the image. Its size will typically match the size of the original disk.

2. In the main window, select the target disk and choose Tools - Save Disk. You can also select multiple disks if needed.

3. When the Image Creation Wizard opens, select whether you want to save the entire disk or only a specific region. Adjust the settings and click Next.

   

4. Choose the directory where the image will be saved. You may select any available disk connected to your PC or upload the image via FTP.

   

Where Are the User’s Files Actually 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.

RAID Recovery Software: Detailed Comparison