Troubleshooting and Recovering Faulty RAID Arrays from NAS Huawei OceanStor Dorado 6000 V6

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.

Are there any specific factors to consider when choosing a NAS Huawei OceanStor Dorado 6000 V6 device to minimize data loss risks?

Yes, there are specific factors to consider when choosing a NAS Huawei OceanStor Dorado 6000 V6 device to minimize data loss risks. Here are some key considerations:

1. Redundancy: Look for a device that offers redundancy features like RAID (Redundant Array of Independent Disks) to protect against data loss in case of disk failures. RAID levels like RAID 1, RAID 5, or RAID 6 can provide data redundancy.
2. Backup and Recovery: Ensure that the NAS device supports regular backup and recovery mechanisms. Look for features like snapshotting, which allows you to take point-in-time copies of your data, and replication, which enables data replication to another device or location for additional protection.
3. Data Protection Features: Check if the NAS device provides data protection features such as data deduplication, compression, and encryption. These features can help reduce storage space requirements, enhance data security, and minimize the risk of data loss.
4. Scalability: Consider the scalability of the NAS device to accommodate your growing data storage needs. A scalable device allows for easy expansion of storage capacity without compromising data availability or risking data loss.
5. High Availability: Look for a NAS device that offers high availability features such as active-active controllers, redundant power supplies, and network connectivity. These features ensure continuous access to data even in the event of hardware failures.
6. Data Integrity Checks: Verify if the NAS device performs regular data integrity checks to identify and repair any potential data corruption issues. Features like checksums or cyclic redundancy checks (CRC) can help detect and mitigate data corruption risks.
7. Monitoring and Alerting: Choose a device that provides comprehensive monitoring and alerting capabilities. This allows you to proactively detect any potential issues or failures and take appropriate actions before they lead to data loss.
8. Service and Support: Ensure that the NAS device is backed by reliable technical support and maintenance services. In case of any issues or data loss events, having access to prompt and knowledgeable support can be crucial.

By considering these factors, you can minimize the risks of data loss when choosing a NAS Huawei OceanStor Dorado 6000 V6 device.

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

Although NAS OceanStor Dorado 6000 V6 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 OceanStor Dorado 6000 V6. 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

OceanStor Dorado 6000 V6 has 32 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 OceanStor Dorado 6000 V6 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