Expert Tips for RAID Array Recovery in NAS Digiever DS-643256-RM Pro+ 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 Digiever 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 drives in a NAS Digiever DS-643256-RM Pro+ device's RAID array impact data recovery and potential loss?

The number of drives in a NAS Digiever DS-643256-RM Pro+ device's RAID array can impact data recovery and potential loss in the following ways:

1. Data Redundancy: RAID arrays use different levels (RAID 0, 1, 5, 6, etc.) to provide data redundancy and fault tolerance. The more drives in the RAID array, the higher the level of redundancy. For example, RAID 5 requires a minimum of three drives, while RAID 6 requires a minimum of four drives. With more drives, the array can withstand multiple drive failures without data loss.
2. Performance: The number of drives in the RAID array can impact the performance of the NAS device. More drives in the array generally result in improved read and write speeds, allowing for faster data access and transfer. However, adding too many drives may also introduce latency due to increased data synchronization overhead.
3. Rebuild Time: When a drive fails in a RAID array, the data from the failed drive needs to be reconstructed onto a replacement drive. The rebuild time is the period during which the array is vulnerable to data loss if another drive fails. With more drives in the array, the rebuild time can be longer, increasing the exposure to potential data loss.
4. Probability of Drive Failure: The more drives in the RAID array, the higher the probability of drive failure. Each drive has a certain failure rate, and as the number of drives increases, the overall probability of at least one drive failure also increases. This increases the risk of data loss before the array can be rebuilt.
5. Cost: Adding more drives to the RAID array increases the cost of the NAS device. However, the cost of potential data loss due to a drive failure may outweigh the initial investment in additional drives.

It is important to consider these factors when configuring the number of drives in a NAS Digiever DS-643256-RM Pro+ device's RAID array to ensure an optimal balance between data protection, performance, and cost.

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

Although NAS DS-643256-RM Pro+ 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 Digiever DS-643256-RM Pro+. 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 Digiever

DS-643256-RM Pro+ 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 Digiever DS-643256-RM Pro+ 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