
- Why Regular Data Recovery Tools Can’t Restore Files from RAID
- Key Information About the NAS Synology DiskStation DS1618+
- How to Remove Hard Disks from Your NAS and Connect Them to a PC
Why Regular Data Recovery Tools Can’t Restore Files from RAID
Conventional hard drives store user data by writing it sequentially across the disk surface, which means an entire file is typically located on a single drive. In contrast, when data is written to a RAID array, each file is split into multiple fragments. These fragments are then distributed and written in sequence across all the drives in the array. Depending on the configuration, fragment sizes can range from 2 KB to 2 MB, so every file is physically stored across several disks at once.
This approach significantly increases read and write performance — after all, writing two halves of a 1 GB file to two drives simultaneously is much faster than writing the full 1 GB to a single disk. However, this same mechanism makes file recovery far more complex.
Different RAID levels use different methods to distribute and protect data. On top of that, manufacturers like Synology often add their own proprietary structures and variations. As a result, data can be written to disks in many different formats, and each requires a specific approach during recovery.
How can data fragmentation impact the read and write speeds, and potential data loss on NAS Synology DiskStation DS1618+ devices?
Data fragmentation can have several impacts on the read and write speeds, as well as potential data loss, on NAS Synology DiskStation DS1618+ devices:
- Read and Write Speeds: Fragmented data can result in slower read and write speeds on the NAS device. When data is fragmented, the system needs to access multiple locations on the storage media to retrieve or write the data, leading to increased seek times and reduced overall performance.
- Increased Disk I/O: Fragmented data requires more disk I/O operations to access and process the scattered data blocks. This can lead to higher latency and reduced throughput, affecting the overall performance of the NAS device.
- Disk Wear and Tear: Fragmentation increases the number of disk head movements required to access fragmented data, resulting in additional wear and tear on the hard drives. This can reduce the lifespan of the drives and increase the chances of disk failures.
- Data Loss Risk: Fragmentation can increase the risk of data loss on NAS devices. If a drive failure occurs and the data is fragmented across multiple drives, the chances of losing a significant portion of data or rendering it unrecoverable may increase. Fragmented data can also complicate data recovery processes in case of file system corruption or accidental deletion.
To mitigate these impacts, it is important to regularly defragment the data on the NAS device. Synology DiskStation DS1618+ devices offer built-in tools like the "Storage Manager" and "Storage Analyzer" that can help identify and defragment fragmented data. Additionally, maintaining sufficient free space on the drives and organizing data in a logical manner can also help minimize fragmentation and improve overall performance and data integrity on the NAS device.
How to Remove Hard Disks from Your NAS and Connect Them to a PC
Although the NAS DiskStation DS1618+ can be accessed over the network, you still need to remove its hard disks and connect them directly to a Windows PC. Only then can the recovery software properly scan and analyze the drives. Follow these steps:
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Power off the NAS and disconnect it from the power source.
WARNING! Before removing any drives, carefully read the device manual. Improper actions may damage both the NAS enclosure and the hard disks in the RAID array.
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Remove the hard disks one by one, gently sliding each drive out of its slot. Remember that hard disks are highly sensitive: any impact or drop can cause serious physical damage.
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Label each hard disk according to its position inside the NAS. The order of the drives is crucial for correct RAID reconstruction.
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Connect the drives to your computer. In this video, we explain which ports you can use to connect hard disks and what to do if your PC does not have enough free connectors.
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Step-by-Step Data Recovery with Hetman RAID Recovery

This program restores data from damaged RAID arrays and is fully compatible with Synology DiskStation DS1618+. Each hard disk in the array contains technical metadata describing how files were written. When launched, Hetman RAID Recovery analyzes this metadata, automatically reconstructs the damaged array, and provides access to its contents. After that, you can browse the recovered disk and save your files. The program can also restore files that were accidentally deleted from the network drive.
How to recover data from a Synology
DiskStation DS1618+ has 6 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);
How to Safely Recover Data from Disk Images
This utility allows you to create a complete copy of a disk and work with the disk image instead of the physical drive. This approach helps protect your data from:
- Overwriting during the recovery process;
- Additional data loss caused by bad sectors;
- User errors.
To create a disk image, follow these steps:
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Ensure you have enough free space to store the image. Its size will typically match the size of the original disk.
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In the main window, select the target disk and choose Tools - Save Disk. You can also select multiple disks if needed.
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When the Image Creation Wizard opens, select whether you want to save the entire disk or only a specific region. Adjust the settings and click Next.

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Choose the directory where the image will be saved. You may select any available disk connected to your PC or upload the image via FTP.

Where Are the User’s Files Actually Stored?
The Synology DiskStation DS1618+ 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.
RAID Recovery Software: Detailed Comparison
| Product | Operating system | RAID controller support | Supported file systems | Virtual RAID controller support | Data recovery from damaged RAID | File preview |
|---|---|---|---|---|---|---|
| Hetman RAID Recovery | Windows, Linux, MacOS | Yes, over 100 controllers | FAT, exFAT, NTFS, ReFS, APFS, HFS+, Ext4, Ext3, Ext2, ReiserFS, Btrfs, VMFS, Hikvision, XFS, UFS, ZFS | Yes | Yes | Yes |
| DiskInternals RAID Recovery | Windows | Yes, over 10 controllers | FAT, NTFS, Ext2/3/4, HFS+ | No | Yes | Yes |
| R-Studio | Windows, Mac, Linux | Yes, over 20 controllers | FAT, NTFS, Ext2/3/4, HFS+ | Yes | Yes | Yes |
| UFS Explorer RAID Recovery | Windows, Mac, Linux | Yes, over 100 controllers | FAT, NTFS, Ext2/3/4, HFS+ | Yes | Yes | Yes |
| EaseUS Data Recovery | Windows | Yes, over 20 controllers | FAT, NTFS, Ext2/3/4, HFS+ | No | Yes | Yes |
| ReclaiMe Free RAID Recovery | Windows | Yes, over 100 controllers | FAT, NTFS, Ext2/3/4, HFS+ | Yes | Yes | Yes |

