NAS Synology DiskStation DS215+ / DS215j RAID Arrays: Data Recovery Methods After Natural 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.

Are there any specific precautions to take while migrating data between NAS Synology DiskStation DS215+ / DS215j devices?

Yes, there are a few precautions you should take while migrating data between NAS Synology DiskStation DS215+ / DS215j devices. Here are some important steps to follow:

1. Backup your data: Before starting the migration process, it is crucial to create a backup of all your important data. This ensures that even if something goes wrong during the migration, your data remains safe.
2. Check compatibility: Ensure that the Synology DiskStation DS215+ / DS215j devices are compatible with each other for data migration. Check the product specifications and compatibility lists provided by Synology to ensure a smooth migration process.
3. Update firmware: Make sure that both the source and destination DiskStations are running the latest firmware versions. Updating the firmware helps in resolving any known issues and ensures compatibility during the migration process.
4. Plan the migration process: Create a detailed plan for the migration process, including the order of data transfer, any specific settings that need to be configured, and the estimated downtime, if any. This helps in minimizing any potential disruptions during the migration.
5. Use the Data Migration Assistant: Synology provides a Data Migration Assistant tool that simplifies the process of transferring data between DiskStation devices. This tool ensures a smooth and efficient migration process.
6. Test the migration process: Before migrating all your data, it is recommended to perform a test migration with a small amount of data. This helps in identifying any issues or errors that may arise during the migration process and allows you to rectify them before migrating the entire dataset.
7. Monitor the migration: Keep a close eye on the migration process to ensure that it is progressing smoothly. Monitor the transfer speed, any error messages, and the overall progress to identify and resolve any issues promptly.
8. Verify the migrated data: Once the migration is complete, verify the integrity and accessibility of the migrated data. Check if all the files and folders are intact and accessible on the new DiskStation.

By following these precautions, you can minimize the risk of data loss or corruption during the migration process and ensure a successful transfer of data between NAS Synology DiskStation DS215+ / DS215j devices.

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

Although NAS DiskStation DS215+ / DS215j 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.

   Go to view

   

   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 DiskStation DS215+ / DS215j. 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.

Go to view

How to recover data from a Synology

DiskStation DS215+ / DS215j has 2 HDD slots, and it supports the following array types:

• Synology Hybrid RAID;
• RAID 1;
• RAID 0;
• Basic;
• JBOD;

NAS supports:

• EXT4;
• EXT3 (External Disk Only);
• FAT32 (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 DiskStation DS215+ / DS215j 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