Repairing a Damaged RAID Array on NAS Idis DR-8364D with Several Disks

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 Idis 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 Idis DR-8364D device's power management settings impact data availability and potential loss?

The power management settings of a NAS (Network Attached Storage) device like the Idis DR-8364D can impact data availability and potential loss in the following ways:

1. Power Interruptions: If the power management settings are not properly configured, sudden power interruptions or outages can occur. This can lead to unexpected shutdowns of the NAS device, resulting in data corruption or loss.
2. Unsaved Data: If the NAS is set to power off or enter a low-power mode too quickly, it may not provide enough time for data to be saved or synchronized properly. This can result in unsaved changes or incomplete backups, leading to data loss or inconsistency.
3. Accessibility: Power management settings that automatically power down the NAS during periods of inactivity may cause delays in accessing data. If the NAS takes a significant amount of time to power up or resume from a sleep mode, it can affect the availability of data when needed urgently.
4. RAID Rebuilds: In a NAS with a RAID configuration, power management settings can impact the rebuild process after a drive failure. If the NAS powers down or enters a low-power mode during a RAID rebuild, it can prolong the process or even lead to a failed rebuild, increasing the risk of data loss.
5. Scheduled Tasks: Power management settings may interfere with scheduled tasks such as backups, replication, or synchronization processes. If the NAS powers off or enters a low-power mode during these tasks, they may be interrupted and leave data in an inconsistent state.

To mitigate these risks, it is essential to configure power management settings carefully. It is recommended to:

• Set appropriate timeouts: Adjust the power-off or sleep timers to allow sufficient time for data saving and synchronization processes to complete.
• Use uninterruptible power supplies (UPS): Connecting the NAS to a UPS can protect it from sudden power interruptions, ensuring uninterrupted operation and data integrity.
• Disable aggressive power-saving modes: Avoid overly aggressive power-saving modes that may cause excessive delays in accessing data or interrupt critical processes.
• Monitor power events: Regularly check power event logs or notifications to identify any issues related to power management and take appropriate actions to prevent data loss.

By properly configuring power management settings and implementing necessary precautions, the risk of data availability issues and potential loss can be minimized.

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

Although NAS DR-8364D 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 Idis DR-8364D. 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 Idis

DR-8364D has 8 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 Idis DR-8364D 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