How to Address Faulty RAID Arrays in NAS Huawei OceanStor Pacific 9550 Data Recovery

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 file system corruption impact data integrity on NAS Huawei OceanStor Pacific 9550 devices?

File system corruption can have a significant impact on data integrity on NAS Huawei OceanStor Pacific 9550 devices. Here are some ways it can affect data integrity:

1. Data Loss: File system corruption can lead to the loss of data stored on the NAS device. Corruption in the file system can make files and directories inaccessible or completely unreadable, resulting in permanent data loss.
2. Data Inconsistency: Corruption in the file system can cause data to become inconsistent. This means that the data may be partially overwritten or contain invalid information. Inconsistent data can lead to errors, data conflicts, and incorrect results when accessing or using the data.
3. Data Modification: File system corruption can modify the data stored on the NAS device without user intervention. This unauthorized modification can alter the content of files, leading to data integrity issues and potential security breaches.
4. Metadata Corruption: The file system metadata, which includes information about file attributes, permissions, and directory structure, can be affected by corruption. Metadata corruption can lead to incorrect file associations, misplacement of files, and difficulties in locating and accessing data.
5. System Instability: File system corruption can cause the NAS device to become unstable or crash frequently. This can disrupt ongoing operations, result in data loss, and impact the overall availability of the device.
6. Data Recovery Challenges: Recovering data from a corrupt file system can be challenging and may require specialized tools or professional assistance. In some cases, data recovery may not be possible, leading to permanent data loss.

To mitigate the impact of file system corruption on data integrity, it is crucial to regularly backup data, implement data redundancy measures, and use reliable file system monitoring and repair tools. Additionally, ensuring proper maintenance, firmware updates, and adherence to best practices for NAS device usage can help minimize the risk of file system corruption.

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

Although NAS OceanStor Pacific 9550 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 Pacific 9550. 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 Pacific 9550 has 60 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 Pacific 9550 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