How to Get Back Data from a Faulty RAID Array in NAS Huawei Data Protection Appliance DPA3210

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 Huawei 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 a NAS Huawei Data Protection Appliance DPA3210 device's cache settings impact data loss risks?

The cache settings of a NAS Huawei Data Protection Appliance DPA3210 device can impact data loss risks in the following ways:

1. Write Cache: The write cache is a temporary storage area where data is stored before being written to the main storage. If the write cache is enabled, it can improve the performance by allowing the system to acknowledge write operations before they are fully committed to the storage. However, if there is a power failure or system crash before the data is written to the main storage, the data in the write cache may be lost, leading to data loss risks.
2. Read Cache: The read cache stores frequently accessed data in a faster storage medium, such as solid-state drives (SSDs), to accelerate read operations. If the read cache is enabled, it can improve the overall read performance. However, if the data in the read cache becomes corrupted or lost, it can result in data inconsistency or data loss risks.
3. RAID Cache: The RAID cache is used in a redundant array of independent disks (RAID) configuration to improve the performance and reliability of the storage system. It can provide faster read and write operations by caching data in memory. However, if there is a power failure or system crash, the data in the RAID cache may be lost, leading to data loss risks.

To mitigate the data loss risks associated with cache settings, it is recommended to:

• Implement a backup strategy: Regularly back up the data stored in the NAS device to an external storage or cloud-based backup solution. This ensures that even if data loss occurs, a recent copy of the data is available for recovery.
• Use a battery backup unit (BBU): Install a BBU to provide temporary power during a power outage. This allows the NAS device to complete pending write operations and ensure data integrity before shutting down.
• Configure cache flush settings: Adjust the cache flush settings to ensure that data is written to the main storage in a timely manner. This reduces the risk of data loss in case of power failure or system crash.
• Monitor cache health: Regularly monitor the health and performance of the cache components, such as SSDs or RAID controllers. This helps identify any potential issues or failures that could lead to data loss.
• Follow best practices: Follow the manufacturer's recommendations and best practices for configuring and managing cache settings. This ensures optimal performance while minimizing data loss risks.

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

Although NAS Data Protection Appliance DPA3210 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 Huawei Data Protection Appliance DPA3210. 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 Huawei

Data Protection Appliance DPA3210 has 12 HDD slots, and it supports the following array types:

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

NAS supports:

• exFAT, VFAT, FAT 12 / 16 / 32;
• NTFS / ReFS;
• APFS / HFS+;
• Ext2 / 3 / 4 / ReiserFS / XFS / UFS / ZFS / Btrfs;
• VMFS / HikvisionFS;

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 Huawei Data Protection Appliance DPA3210 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