Professional Tips for Recovering Data from a Failed NAS Promise Vess 1840 RAID Configuration

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 Promise 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 the number of concurrent users or clients accessing a NAS Promise Vess 1840 device affect data loss risks?

The number of concurrent users or clients accessing a NAS Promise Vess 1840 device can affect data loss risks in the following ways:

1. Network congestion: As the number of concurrent users accessing the NAS device increases, the network traffic also increases. This can lead to network congestion, resulting in slower data transfer speeds and potential data loss due to timeouts or dropped connections.
2. Performance degradation: With more users accessing the NAS device simultaneously, the device's performance may degrade. This can lead to delays in file access, data corruption, or even system crashes, increasing the risk of data loss.
3. Increased probability of user errors: With more concurrent users, the likelihood of accidental file deletions, overwrites, or modifications also increases. Human errors can be a significant cause of data loss, and the more users accessing the device, the higher the chances of such errors occurring.
4. Security vulnerabilities: The more concurrent users accessing the NAS device, the larger the attack surface for potential security breaches. If any user's account gets compromised or if there are vulnerabilities in the system, it can lead to unauthorized access, data breaches, or data loss.
5. Insufficient resources: A higher number of concurrent users can put a strain on the NAS device's resources, such as CPU, memory, or storage capacity. If the device is not adequately equipped to handle the load, it may result in data loss or corruption.

To mitigate these risks, it is important to ensure that the NAS device is properly configured, regularly maintained, and equipped with sufficient resources to handle the expected number of concurrent users. Implementing user access controls, regular backups, and monitoring mechanisms can also help minimize the chances of data loss.

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

Although NAS Vess 1840 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 Promise Vess 1840. 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 Promise

Vess 1840 has 16 HDD slots, and it supports the following array types:

• RAID 0;
• RAID 1;
• RAID 1E;
• RAID 3;
• RAID 5;
• RAID 6;
• RAID 30;
• 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 Promise Vess 1840 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