RAID Array Recovery on NAS QNAP TES-3085U(QTS): How to Handle It When It Fails

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 QNAP 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 QNAP TES-3085U(QTS) devices?

Regular disk health monitoring and analysis can help in preventing potential data loss on NAS QNAP TES-3085U(QTS) devices in the following ways:

1. Early detection of disk failures: Disk health monitoring tools can constantly monitor the SMART (Self-Monitoring, Analysis, and Reporting Technology) data of the disks in the NAS. This allows for the early detection of any signs of disk failure, such as bad sectors, high temperature, or increased error rates. By identifying these issues early on, you can take proactive measures like replacing the failing disk before it completely fails and causes data loss.
2. Predictive failure analysis: Some disk health monitoring tools can analyze the historical SMART data and predict the likelihood of a disk failure in the near future. This allows you to proactively replace the predicted failing disks before they actually fail, minimizing the risk of data loss.
3. RAID array monitoring: If you have set up a RAID configuration on your NAS, disk health monitoring can help in monitoring the status of the RAID array. It can alert you if any disks in the array fail or if there are any issues with the RAID array itself. This allows you to take immediate action to rebuild the array or replace the failed disks, ensuring data integrity and preventing data loss.
4. Temperature monitoring: Overheating can be a common cause of disk failures. Disk health monitoring tools can monitor the temperature of the disks and alert you if they exceed safe operating limits. This allows you to take corrective actions like improving the cooling system or relocating the NAS to a cooler environment, preventing potential data loss due to overheating.
5. Regular data scrubbing: Disk health monitoring tools can also perform regular data scrubbing, which involves reading and verifying the integrity of data stored on the disks. This helps in identifying and correcting any silent data corruption issues before they lead to data loss.
6. Backup monitoring: In addition to disk health monitoring, it is crucial to regularly monitor the status and health of your backup system. This ensures that your backups are up to date, accessible, and in a healthy state, providing an additional layer of protection against data loss.

By regularly monitoring and analyzing the health of the disks in your NAS QNAP TES-3085U(QTS) device, you can proactively identify and address any potential issues that could lead to data loss. This helps in maintaining the reliability and integrity of your data storage system.

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

Although NAS TES-3085U(QTS) 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 QNAP TES-3085U(QTS). 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 QNAP

TES-3085U(QTS) has 30 HDD slots, and it supports the following array types:

• RAID 50;
• RAID 60;
• RAID 6;
• RAID 5;
• RAID 10;
• RAID 0;
• RAID 1;
• JBOD;

NAS supports:

• ZFS;
• EXT4;
• EXT3;
• exFAT;
• FAT32 (External Disk Only);
• NTFS (External Disk Only);
• HFS+ (External Disk Read Only);

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 QNAP TES-3085U(QTS) network-attached storage keeps QTS (QuTS hero) 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