Essential Tips for RAID Array Recovery in NAS Digiever DS-4005 Systems

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 a NAS Digiever DS-4005 device's power management settings impact data availability and potential loss?

The power management settings of a NAS (Network Attached Storage) device like the Digiever DS-4005 can have a significant impact on data availability and potential loss. Here are a few ways these settings can affect the device:

1. Power-off schedule: If the power management settings are configured to automatically power off the NAS device during certain hours or periods of inactivity, it can lead to data unavailability during those times. If users or applications require access to the data during the power-off period, it can disrupt their operations and cause inconvenience.
2. Data synchronization: NAS devices often use RAID (Redundant Array of Independent Disks) technology to provide data redundancy and protection against disk failures. However, if the power management settings cause the NAS device to turn off abruptly, it can interrupt the synchronization process between the disks. This can result in data inconsistencies or even data loss if the synchronization process was not completed properly.
3. Disk spin-down: Some NAS devices have the capability to spin down or idle the hard drives when they are not in use for a certain period. While this can save power, it can also lead to delays in accessing the data when needed. If a user or application tries to access data from a spun-down disk, there will be a delay as the disk needs to spin up to the operational speed. This delay can impact the user experience and productivity.
4. Power outage protection: Power management settings can also affect the NAS device's ability to handle power outages. If the settings are not configured properly, sudden power loss can result in data corruption or loss. For example, if the NAS device is not equipped with a battery backup or if the power-off process is not gracefully handled, ongoing read/write operations may not be completed, leading to data inconsistencies or even data loss.

To mitigate the potential impact on data availability and loss, it is important to carefully configure the power management settings of the Digiever DS-4005 NAS device. Consider factors such as the required availability of data, the expected usage patterns, and the importance of power saving versus immediate data access. Additionally, implementing appropriate backup strategies, uninterruptible power supplies (UPS), and monitoring systems can help ensure data integrity and availability.

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

Although NAS DS-4005 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-4005. 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-4005 has 4 HDD slots, and it supports the following array types:

• RAID 0;
• RAID 1;
• RAID 5;
• RAID 6;
• 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-4005 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