- 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 QNAP 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 QNAP ES1640dc v2 device's RAID array impact data recovery and potential loss?
The number of drives in a NAS QNAP ES1640dc v2 device's RAID array can impact data recovery and potential loss in the following ways:
- RAID Level: The number of drives determines the RAID level that can be implemented. Different RAID levels offer varying levels of data redundancy and performance. For example, RAID 5 requires a minimum of three drives, while RAID 6 requires at least four drives. Higher RAID levels provide better fault tolerance and protection against drive failures, reducing the risk of data loss.
- Data Redundancy: The more drives in the RAID array, the higher the level of data redundancy. Redundancy means that if one or more drives fail, the data can still be accessed and recovered from the remaining drives. With more drives, the RAID array can sustain multiple drive failures without losing data.
- Rebuild Time: When a drive fails in a RAID array, the data needs to be rebuilt onto a replacement drive. The larger the number of drives in the array, the longer it takes to rebuild the data. During the rebuild process, the array is in a vulnerable state, and if another drive fails, it can lead to data loss. So, a larger number of drives increases the risk of data loss during the rebuild process.
- Failure Probability: With more drives in a RAID array, the probability of drive failures increases. Each drive has a certain failure rate, and as the number of drives increases, so does the likelihood of encountering a drive failure. If multiple drives fail simultaneously or in close succession, it can result in data loss.
- Data Recovery Cost: In case of data loss, the cost of data recovery can vary depending on the number of drives in the RAID array. Data recovery from a larger RAID array with more drives can be more complex and expensive compared to a smaller array. This is because the recovery process involves handling multiple drives and reconstructing the data from them.
It is important to carefully consider the number of drives in a NAS QNAP ES1640dc v2 device's RAID array to strike a balance between data redundancy, performance, and the risk of data loss. Regular backups and monitoring the health of the drives can also help mitigate potential data loss risks.
How to take hard disks out of the NAS and connect them to a PC?
Although NAS ES1640dc v2 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:
-
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.
-
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.
-
Make sure to mark each hard disk in accordance with how they were installed inside the NAS.
-
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
Restoring data with Hetman RAID Recovery
This program recovers data from damaged RAID arrays and is fully compatible with QNAP ES1640dc v2. 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.
How to recover data from a QNAP
ES1640dc v2 has 16 HDD slots, and it supports the following array types:
- RAID 50;
- RAID 60;
- RAID 6;
- RAID 5;
- RAID 10;
- RAID 0;
- RAID 1;
- JBOD;
NAS supports:
- ZFS;
- EXT4;
- EXT3;
- exFAT;
- 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:
-
Make sure that you have enough free space to save the image. The image file size usually equals the disk size.
-
Select the disk in the main window, and choose from the menu Tools – Save Disk. You can select multiple disks to be saved.
-
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.
-
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 QNAP ES1640dc v2 network-attached storage keeps QTS (QuTS hero) 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 |
Data recovery from a NAS QNAP ES1640dc v2 device can be challenging if the storage disks have been overwritten or reformatted. In such cases, the chances of recovering the data will depend on several factors:
It is important to note that data recovery from overwritten or reformatted disks is not guaranteed, and it is always recommended to consult with a professional data recovery service for the best possible chance of successful recovery.