- 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?
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 WD 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 the number of drives in a NAS WD My Cloud PR2100 device's RAID array impact data recovery and potential loss?
The number of drives in a RAID array in a NAS (Network Attached Storage) device like the WD My Cloud PR2100 can have an impact on data recovery and potential loss in the following ways:
- Data Redundancy: RAID arrays provide data redundancy by distributing data across multiple drives. The most common RAID levels used in NAS devices are RAID 1 (mirroring) and RAID 5 (striping with parity). In RAID 1, data is mirrored on two drives, while in RAID 5, data is striped across multiple drives with parity information. The more drives in the array, the higher the level of redundancy, which can help protect against data loss in the event of a drive failure.
- Increased Fault Tolerance: With more drives in the array, the NAS device can withstand multiple drive failures without losing data. For example, in a RAID 5 array with four drives, one drive can fail, and the data can still be accessed and recovered from the remaining drives. However, if another drive fails before the failed drive is replaced and rebuilt, data loss can occur. Having more drives in the array reduces the risk of data loss during the rebuilding process.
- Rebuilding Time: When a drive fails in a RAID array, the data from the failed drive needs to be rebuilt onto a replacement drive. During this process, the remaining drives in the array are under increased stress, which can increase the likelihood of another drive failure. With a larger number of drives in the array, the rebuilding process can take longer, increasing the exposure to potential data loss.
- Cost: Adding more drives to a RAID array increases the overall cost of the NAS device. However, the added cost can be justified by the increased data redundancy and fault tolerance provided by a larger array.
In summary, having more drives in a NAS device's RAID array can improve data redundancy, fault tolerance, and protection against drive failures. However, it can also increase the time required for rebuilding and the overall cost of the device.
How to take hard disks out of the NAS and connect them to a PC?
Although NAS My Cloud PR2100 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:
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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.
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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.
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Make sure to mark each hard disk in accordance with how they were installed inside the NAS.
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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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Restoring data with Hetman RAID Recovery
This program recovers data from damaged RAID arrays and is fully compatible with WD My Cloud PR2100. 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.
My Cloud PR2100 has 2 HDD slots, and it supports the following array types:
- RAID 0;
- RAID 1;
- JBOD;
NAS supports:
- Ext2;
- Ext3;
- Ext4;
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:
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Make sure that you have enough free space to save the image. The image file size usually equals the disk size.
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Select the disk in the main window, and choose from the menu Tools – Save Disk. You can select multiple disks to be saved.
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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.
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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 WD My Cloud PR2100 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
| Product | Operating system | License type | RAID controller support | Supported file systems | Virtual RAID controller support | Data recovery from damaged RAID | File preview |
|---|---|---|---|---|---|---|---|
| Hetman RAID Recovery | Windows | Paid | Yes, over 100 controllers | FAT, NTFS, Ext2/3/4, HFS+ | Yes | Yes | Yes |
| DiskInternals RAID Recovery | Windows | Paid | Yes, over 100 controllers | FAT, NTFS, Ext2/3/4, HFS+ | No | Yes | Yes |
| R-Studio | Windows, Mac, Linux | Paid | Yes, over 200 controllers | FAT, NTFS, Ext2/3/4, HFS+ | Yes | Yes | Yes |
| UFS Explorer RAID Recovery | Windows, Mac, Linux | Paid | Yes, over 1,000 controllers | FAT, NTFS, Ext2/3/4, HFS+ | Yes | Yes | Yes |
| EaseUS Data Recovery | Windows | Paid | Yes, over 20 controllers | FAT, NTFS, Ext2/3/4, HFS+ | No | Yes | Yes |
| ReclaiMe Free RAID Recovery | Windows | Free | Yes, over 100 controllers | FAT, NTFS, Ext2/3/4, HFS+ | Yes | Yes | Yes |
Yes, there are several software solutions available for data recovery from WD My Cloud PR2100 devices with S.M.A.R.T. errors. Some of the popular options include:
It's important to note that data recovery from NAS devices with S.M.A.R.T. errors can be challenging, and there is no guarantee of 100% success. It's recommended to consult with a professional data recovery service if the data is critical or valuable.