How to recover data from Thecus N7700SAS NAS

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.

How can regular disk health monitoring and analysis help in preventing potential data loss on NAS Thecus N7700SAS devices?

Regular disk health monitoring and analysis can help in preventing potential data loss on NAS Thecus N7700SAS devices in the following ways:

1. Early detection of disk failures: By regularly monitoring the health of the disks, you can identify any signs of potential failures such as bad sectors, read/write errors, or abnormal temperature levels. This allows you to take proactive measures like replacing the failing disks before they completely fail and cause data loss.
2. RAID array maintenance: NAS devices like Thecus N7700SAS often use RAID configurations to provide data redundancy and protection against disk failures. Regular disk health monitoring helps in identifying any issues with individual disks in the RAID array. By replacing the failing disks promptly, you can ensure the integrity and availability of your data.
3. SMART monitoring: The Self-Monitoring, Analysis, and Reporting Technology (SMART) feature in hard drives provides detailed information about the drive's health and performance. By regularly analyzing the SMART data, you can identify any warning signs or anomalies that may indicate an impending disk failure. This enables you to take appropriate actions to prevent data loss.
4. Predictive failure analysis: Some disk monitoring tools offer predictive failure analysis, which uses historical data and statistical models to predict the likelihood of disk failures. By analyzing this data, you can identify disks that are more likely to fail in the near future and replace them proactively, minimizing the risk of data loss.
5. Data backup and recovery: Regular disk health monitoring can remind you to regularly backup your data and ensure that your backup systems are functioning properly. In case of a disk failure or data loss event, having up-to-date backups can significantly reduce the impact and recovery time.

Overall, regular disk health monitoring and analysis provide valuable insights into the condition of your NAS disks, allowing you to take preventive measures, maintain data integrity, and minimize the risk of potential data loss.

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

Although NAS N7700SAS 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 N7700SAS. 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

N7700SAS has 7 HDD slots, and it supports the following array types:

• RAID 0;
• RAID 1;
• RAID 5;
• RAID 6;
• RAID 50;
• RAID 60;
• 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 N7700SAS 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