- 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 Thecus 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 storage tiering or caching strategies impact data availability and potential loss on NAS Thecus N16850 devices?
Storage tiering and caching strategies can have a significant impact on data availability and potential loss on NAS Thecus N16850 devices. Here are a few ways in which these strategies can affect data availability and potential loss:
- Improved Performance: Storage tiering and caching strategies can improve the overall performance of the NAS device by ensuring that frequently accessed data is readily available in the faster storage tiers or cache. This can enhance data availability as users can access their data quickly without any noticeable delays.
- Reduced Latency: By utilizing caching techniques, frequently accessed data can be stored in the cache, which resides in faster storage media such as solid-state drives (SSDs). This reduces the latency in retrieving data, ensuring faster access and improved data availability.
- Increased Fault Tolerance: Some storage tiering strategies involve redundancy by replicating data across multiple storage tiers. This redundancy can enhance fault tolerance and data availability. In the event of a drive failure, the redundant copies of data can be used to ensure that the data remains accessible.
- Data Loss Risks: However, there are potential risks associated with storage tiering and caching strategies. If data is primarily stored in the cache or faster storage tiers and not adequately backed up, there is a risk of data loss in case of a cache failure or storage tier failure. It is crucial to implement appropriate backup and disaster recovery measures to mitigate these risks.
- Data Placement Policies: The effectiveness of storage tiering and caching strategies depends on the data placement policies employed. If the policies are not well-optimized or if the data is not correctly classified based on access patterns, it may result in suboptimal performance or limited data availability.
To ensure data availability and mitigate potential loss, it is essential to carefully plan and implement storage tiering and caching strategies, consider redundancy and fault tolerance mechanisms, regularly backup critical data, and monitor the health and performance of the NAS device.
How to take hard disks out of the NAS and connect them to a PC?
Although NAS N16850 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 Thecus N16850. 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.
N16850 has 16 HDD slots, and it supports the following array types:
- RAID 0;
- RAID 1;
- RAID 5;
- RAID 6;
- RAID 50;
- RAID 60;
- RAID 10;
- JBOD;
NAS supports:
- EXT3;
- EXT4;
- XFS;
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 Thecus N16850 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 |
To eject hard drives from a Thecus N16850 NAS and connect them to a Windows computer, follow these steps:
To connect the ejected hard drive(s) to a Windows computer:
Remember to handle the hard drives with care and avoid touching the exposed circuitry or any sensitive components.