- 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 ZyXel 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 ZyXel NAS520 device's RAID array impact data recovery and potential loss?
The number of drives in a NAS ZyXel NAS520 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 1 (mirroring) requires a minimum of two drives, while RAID 5 (striping with parity) requires a minimum of three drives. The RAID level chosen affects the ability to recover data in case of drive failure.
- Data Redundancy: The more drives in the RAID array, the higher the level of data redundancy. With more drives, the RAID array can sustain multiple drive failures without losing data. For example, RAID 5 can tolerate the failure of a single drive, while RAID 6 can withstand the failure of two drives. Having more drives in the array reduces the risk of data loss.
- Rebuild Time: When a drive fails in a RAID array, the data from the failed drive needs to be rebuilt onto a replacement drive. The larger the RAID array (more drives), the longer it takes to rebuild the array. During this rebuild process, the remaining drives are under increased stress, increasing the risk of additional drive failures. If multiple drives fail during the rebuild, it can lead to data loss.
- Performance Impact: The number of drives impacts the performance of the RAID array. In general, more drives in the array provide higher performance due to increased data distribution and parallelism. However, adding more drives can also introduce more points of failure and increase the risk of data loss if multiple drives fail simultaneously.
- Cost: The number of drives in the RAID array affects the cost of the NAS device. More drives mean a higher cost of hardware, as well as increased power consumption and maintenance costs. It is essential to balance the cost with the desired level of data redundancy and performance.
In summary, the number of drives in a ZyXel NAS520 device's RAID array impacts data recovery and potential loss by influencing the RAID level, data redundancy, rebuild time, performance, and cost. It is crucial to choose the appropriate number of drives based on the required level of data protection, performance needs, and budget constraints.
How to take hard disks out of the NAS and connect them to a PC?
Although NAS NAS520 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 ZyXel NAS520. 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.
NAS520 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 ZyXel NAS520 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, it is possible to recover data from a ZyXel NAS520 device even if it is experiencing slow performance or file access issues. Here are a few steps you can try:
If none of these steps work, it may be necessary to seek professional data recovery services. They can help recover data from the NAS device even if it is experiencing severe performance issues.