NAS Synology Rack Station RS818RP+ / RS818+ RAID Arrays: Data Recovery Techniques Following Component Wear

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.

How can data fragmentation impact data availability and potential loss on NAS Synology Rack Station RS818RP+ / RS818+ devices?

Data fragmentation can have several impacts on data availability and potential loss on NAS Synology Rack Station RS818RP+ / RS818+ devices:

1. Reduced Performance: Fragmented data requires the NAS device to spend more time searching for and accessing scattered data blocks, resulting in slower read and write speeds. This can lead to reduced overall performance and slower data availability.
2. Increased Disk Wear: Fragmentation can cause excessive disk head movement as the NAS device tries to access scattered data blocks. This increased movement can lead to increased wear and tear on the hard drives, potentially shortening their lifespan and increasing the risk of data loss.
3. Increased Risk of Data Loss: Fragmented data is more susceptible to data loss in case of disk failure. If a fragmented file is spread across multiple disks and one of them fails, it becomes difficult to recover the complete file. This can result in partial or complete data loss, depending on the level of fragmentation.
4. Longer Backup and Restore Times: Fragmented data can significantly increase the time required for backup and restore operations. Backup processes may take longer as the NAS device needs to read scattered data blocks from different areas of the disk. Similarly, restoring fragmented data can be time-consuming as the device needs to locate and reassemble the scattered blocks.
5. Difficulty in Data Recovery: In the event of data corruption or accidental deletion, fragmented data can make data recovery more challenging. The scattered nature of the data makes it harder for data recovery tools to locate and recover the complete files, increasing the risk of permanent data loss.

To mitigate the impact of data fragmentation, it is recommended to regularly defragment the NAS device's hard drives. This process rearranges the fragmented data blocks, optimizing data storage and improving overall performance. Additionally, implementing a proper backup strategy, including off-site backups, can help protect against data loss caused by fragmentation or other issues.

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

Although NAS Rack Station RS818RP+ / RS818+ 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 Rack Station RS818RP+ / RS818+. 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

Rack Station RS818RP+ / RS818+ has 4 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 Rack Station RS818RP+ / RS818+ 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