RAID Controller Failure on NAS Synology High Density HD6500: Data Recovery Tips and Consequences

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 Synology also introduce some modifications to this process, and that is why data can be written to hard disk in a wide variety of ways.

Are there any specific factors to consider when choosing a NAS Synology High Density HD6500 device to minimize data loss risks?

Yes, there are several factors to consider when choosing a NAS Synology High Density HD6500 device to minimize data loss risks. Some of these factors include:

1. Redundancy: Look for a NAS device that supports RAID (Redundant Array of Independent Disks) configurations. RAID allows for data to be distributed across multiple drives, providing redundancy and protection against drive failures.
2. Drive compatibility: Ensure that the NAS device supports the use of reliable and compatible hard drives. It is recommended to use NAS-specific drives that are designed for 24/7 operation and have features like vibration resistance and error recovery controls.
3. Backup options: Consider the backup options provided by the NAS device. Look for features like built-in backup applications, support for external backups, and cloud backup integration. Having multiple backup options will help protect your data in case of hardware failure or other unforeseen events.
4. Data protection features: Check if the NAS device offers data protection features such as snapshot technology, which allows you to take point-in-time snapshots of your data for quick recovery in case of accidental deletion or corruption.
5. Power supply and cooling: Ensure that the NAS device has a reliable power supply and efficient cooling mechanisms. Power outages and overheating can lead to data loss, so it is important to have a stable power source and proper ventilation for the device.
6. Firmware updates and security: Regular firmware updates are essential for maintaining the security and stability of the NAS device. Look for a manufacturer that provides frequent updates and has a good track record of addressing security vulnerabilities.
7. Scalability: Consider the scalability options of the NAS device. Choose a device that allows for easy expansion of storage capacity as your data needs grow. This will help prevent data loss due to running out of storage space.

By considering these factors, you can minimize the risks of data loss and ensure the safety and integrity of your data on a NAS Synology High Density HD6500 device.

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

Although NAS High Density HD6500 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 Synology High Density HD6500. 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 Synology

High Density HD6500 has 60 HDD slots, and it supports the following array types:

• Synology Hybrid RAID (SHR);
• RAID 6;
• RAID 5;
• RAID 10;
• RAID 1;
• RAID 0;
• Basic;
• JBOD;

NAS supports:

• Btrfs;
• EXT4;
• EXT3 (External Disk Only);
• FAT32 (External Disk Only);
• exFAT (External Disk Only);
• NTFS (External Disk Only);
• HFS+ (External Disk Read Only);

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 Synology High Density HD6500 network-attached storage keeps DSM (DiskStation Manager) 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