- 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 Promise 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 Promise Vess 1740 devices?
Storage tiering and caching strategies can have a significant impact on data availability and potential loss on NAS Promise Vess 1740 devices. Here are some ways these strategies can affect data:
- Improved Data Availability: Storage tiering allows data to be dynamically moved between different tiers of storage based on its usage patterns. By automatically moving frequently accessed data to faster storage tiers (such as SSDs) and less frequently accessed data to slower tiers (such as HDDs), storage tiering ensures that frequently accessed data is readily available, improving data availability.
- Reduced Potential Data Loss: Caching strategies, such as read and write caching, can help improve performance by temporarily storing frequently accessed data in faster cache memory. This reduces the need to retrieve data from slower storage media, reducing latency. In the event of a storage failure, if data is already cached, it can be quickly retrieved, minimizing potential data loss.
- Redundancy and Data Protection: Some storage tiering and caching strategies, especially those implemented in RAID configurations, provide data redundancy and protection against potential data loss. RAID levels like RAID 1, RAID 5, or RAID 6 can be used to create redundant copies of data across multiple drives, ensuring that even if a drive fails, the data remains accessible and intact.
However, it's important to note that while these strategies can improve data availability and reduce potential loss, they do not provide complete data protection. Other measures like regular backups, disaster recovery plans, and data replication should also be considered to ensure comprehensive data protection and availability.
How to take hard disks out of the NAS and connect them to a PC?
Although NAS Vess 1740 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 Promise Vess 1740. 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 Promise
Vess 1740 has 16 HDD slots, and it supports the following array types:
- RAID 0;
- RAID 1;
- RAID 1E;
- RAID 3;
- RAID 5;
- RAID 6;
- RAID 30;
- RAID 50;
- RAID 60;
- JBOD;
NAS supports:
- exFAT, VFAT, FAT 12 / 16 / 32;
- NTFS / ReFS;
- APFS / HFS+;
- Ext2 / 3 / 4 / ReiserFS / XFS / UFS / ZFS / Btrfs;
- VMFS / HikvisionFS;
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 Promise Vess 1740 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, data recovery from a NAS Promise Vess 1740 device can still be possible even if the device is experiencing network congestion or bandwidth issues. However, the process may be slower and more challenging due to the limitations imposed by the network congestion.
In such cases, it is recommended to follow these steps:
Remember to always back up your important data regularly to prevent data loss and minimize the impact of any unforeseen issues.