NAS QNAP VS-2104L RAID Arrays: Recovering Data from Mechanical and Logical Failures

Contents

• 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?
  • Restoring data with Hetman RAID Recovery
  • Safe recovery from disk images
  • Where are user’s files stored?
  • Comparison of software for RAID recovery

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 data redundancy techniques such as mirroring or replication enhance data availability and protect against loss on NAS QNAP VS-2104L devices?

Data redundancy techniques such as mirroring or replication can enhance data availability and protect against loss on NAS QNAP VS-2104L devices in the following ways:

1. Mirroring: Mirroring involves creating an exact copy of the data on one disk to another disk in real-time. In case of a disk failure, the mirrored disk can take over seamlessly, ensuring continuous availability of data. QNAP VS-2104L devices support RAID 1, which is a mirroring technique that provides redundancy by writing data to two disks simultaneously. This protects against data loss if one disk fails.
2. Replication: Replication involves creating multiple copies of data and distributing them across different devices or locations. QNAP VS-2104L devices support various replication methods, such as remote replication or snapshot replication. Remote replication allows you to replicate data to a remote QNAP NAS, ensuring data availability even if the primary device fails. Snapshot replication creates point-in-time copies of data, allowing you to restore data to a previous state in case of accidental deletion or corruption.
3. High Availability (HA): QNAP VS-2104L devices also support High Availability, which ensures continuous availability of data by utilizing two NAS devices in an active-passive configuration. In this setup, one NAS serves as the active device, while the other remains in standby. If the active device fails, the standby device takes over seamlessly, minimizing downtime and data loss.
4. Data Scrubbing: QNAP VS-2104L devices offer data scrubbing functionality, which periodically checks and repairs data integrity issues on the disks. This helps to identify and correct errors before they lead to data loss or corruption.

By implementing these data redundancy techniques, QNAP VS-2104L devices can enhance data availability by providing continuous access to data even in the event of hardware failures or disasters. Additionally, they protect against data loss by creating redundant copies of data and allowing for easy restoration in case of accidental deletion or corruption.

How to take hard disks out of the NAS and connect them to a PC?

Although NAS VS-2104L 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:

1. 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.

2. 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.

3. Make sure to mark each hard disk in accordance with how they were installed inside the NAS.

4. 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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   How to Order Remote Data Recovery

Restoring data with Hetman RAID Recovery

This program recovers data from damaged RAID arrays and is fully compatible with QNAP VS-2104L. 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.

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How to recover data from a QNAP

VS-2104L has 2 HDD slots, and it supports the following array types:

• RAID 1;

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:

1. Make sure that you have enough free space to save the image. The image file size usually equals the disk size.

2. Select the disk in the main window, and choose from the menu Tools – Save Disk. You can select multiple disks to be saved.

3. 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.

   

4. 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 VS-2104L 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