What is SSH and how does it work?

SSH, which stands for Secure Shell, is a cryptographic network protocol used for secure communication and remote administration over an unsecured network. It provides a secure channel for encrypted communication between two devices, typically a client and a server.Here's how SSH works:Connection Establishment: The client initiates a connection request to the server using the SSH protocol. The server listens on a specific port (usually port 22) for incoming SSH connections.Key Exchange: During the initial connection, the client and server perform a key exchange. This involves negotiating encryption algorithms, generating session keys, and verifying the server's authenticity.User Authentication: Once the key exchange is complete, the client needs to authenticate itself to the server. SSH supports various authentication methods like password-based authentication, public key authentication, and more.Secure Communication: After successful authentication, SSH sets up a secure encrypted channel between the client and server. All subsequent data transmitted over this channel is encrypted to protect it from eavesdropping or tampering.Remote Shell or Command Execution: With the secure connection established, the client can now remotely execute commands on the server or open a remote shell session. The server processes the commands and sends the output back to the client.SSH also supports other features like file transfer (SCP and SFTP), port forwarding, and tunneling, which allow secure access to services running on remote servers.Overall, SSH ensures secure communication and remote administration by encrypting data, verifying server authenticity, and providing strong user authentication mechanisms.

How does the NAS QNAP VS-5020 utilize SSH protocol for secure remote access?

The NAS QNAP VS-5020 utilizes the SSH (Secure Shell) protocol for secure remote access by allowing users to establish a secure encrypted connection to the NAS device over a network. Here's how it works:SSH Server: The NAS device acts as an SSH server, running an SSH daemon that listens for incoming SSH connections.Authentication: When a user wants to remotely access the NAS, they initiate an SSH connection using an SSH client. The SSH server on the NAS prompts the user for authentication credentials, typically a username and password.Encryption: Once the user's credentials are provided, the SSH server verifies them and establishes an encrypted session between the client and server. This encryption ensures that the data transmitted over the network cannot be intercepted or tampered with by unauthorized parties.Secure Shell: Once the SSH connection is established, the user gains access to a command-line interface (CLI) on the NAS device. The user can remotely execute commands, manage files, and perform various administrative tasks on the NAS.Secure File Transfer: SSH also enables secure file transfer between the client and the NAS. Users can securely transfer files to and from the NAS using the Secure Copy Protocol (SCP) or the Secure File Transfer Protocol (SFTP), both of which are supported by SSH.Tunneling: SSH also supports tunneling, allowing users to securely access other network services running on the NAS device or behind it. This feature enables secure access to services like web servers, databases, or other applications hosted on the NAS.Overall, by utilizing the SSH protocol, the NAS QNAP VS-5020 ensures that remote access to the device is secure, encrypted, and protected from unauthorized access or data interception.

What are the advantages and features of SSH in the context of NAS QNAP VS-5020?

The SSH (Secure Shell) protocol provides secure remote access and file transfer capabilities. In the context of a NAS (Network Attached Storage) like the QNAP VS-5020, SSH offers several advantages and features:Secure remote access: SSH allows you to securely access your NAS from a remote location over an encrypted connection. This ensures that your data and credentials are protected from unauthorized access.Encrypted file transfer: With SSH, you can securely transfer files between your local machine and the NAS. The encryption ensures that the data is protected during transit, reducing the risk of interception or tampering.Command-line interface: SSH provides a command-line interface (CLI) to interact with the NAS. This allows for advanced configuration, administration, and troubleshooting tasks that may not be available through a graphical user interface (GUI).Secure remote management: SSH enables secure remote management of the NAS. You can perform various administrative tasks, such as configuring network settings, managing users and permissions, and monitoring system resources, all from a remote location.Customization and automation: SSH allows you to automate tasks on the NAS by running scripts or commands remotely. This can help streamline repetitive tasks and improve efficiency.Compatibility and flexibility: SSH is a widely supported protocol and can be used with various operating systems and devices. It provides flexibility in accessing and managing the NAS from different platforms, including Windows, macOS, and Linux.Two-factor authentication (2FA): Some NAS devices, including QNAP models, support two-factor authentication for SSH access. This adds an extra layer of security by requiring a second authentication factor, such as a time-based one-time password (TOTP) or a hardware token.It's important to note that enabling SSH on a NAS should be done with caution and proper security measures. Strong passwords, firewall rules, and regular updates should be implemented to ensure the security of your NAS and data.

Key Features of NAS QNAP VS-5020 Data Recovery for Home Enthusiasts

Name: How to recover data from a QNAP
Uploaded: 2025-10-16T08:53:56+03:00
Description: How to recover data from a QNAP

Has your NAS QNAP VS-5020 suddenly lost its network drive and you’re unsure what to do next? Did the RAID array collapse, making your files inaccessible? Is the device throwing errors during startup? Perhaps you accidentally rebuilt the RAID array or several hard drives failed at the same time?

Key Features of NAS QNAP VS-5020 Data Recovery for Home Enthusiasts

Data Recovery Tool

QNAP VS-5020 NAS Data Recovery in 2025

In this step-by-step tutorial, we’ll show you how to rebuild your RAID and recover data from an VS-5020. We’ll walk through the most common causes of failure and demonstrate proven methods to restore files from a lost or degraded RAID array.

Contents

Why Regular Data Recovery Tools Can’t Restore Files from RAID
Key Information About the NAS QNAP VS-5020
How to Remove Hard Disks from Your NAS and Connect Them to a PC

RAID Recovery™ 2.8

Recover data from damaged RAID arrays inaccessible from a computer.

Download

Why Regular Data Recovery Tools Can’t Restore Files from RAID

Conventional hard drives store user data by writing it sequentially across the disk surface, which means an entire file is typically located on a single drive. In contrast, when data is written to a RAID array, each file is split into multiple fragments. These fragments are then distributed and written in sequence across all the drives in the array. Depending on the configuration, fragment sizes can range from 2 KB to 2 MB, so every file is physically stored across several disks at once.

This approach significantly increases read and write performance — after all, writing two halves of a 1 GB file to two drives simultaneously is much faster than writing the full 1 GB to a single disk. However, this same mechanism makes file recovery far more complex.

Different RAID levels use different methods to distribute and protect data. On top of that, manufacturers like QNAP often add their own proprietary structures and variations. As a result, data can be written to disks in many different formats, and each requires a specific approach during recovery.

Are there any common mistakes or oversights made by users that can lead to data loss on NAS QNAP VS-5020 devices?

While it is difficult to pinpoint specific mistakes or oversights that can lead to data loss on NAS QNAP VS-5020 devices, there are some common scenarios that users should be cautious about. Here are a few potential mistakes or oversights:

Lack of proper backup: Many users rely solely on their NAS device for data storage without implementing a backup strategy. If the NAS experiences hardware failure, accidental deletion, or data corruption, it can result in permanent data loss. It is crucial to have a backup system in place to mitigate such risks.
Insufficient RAID configuration: The QNAP VS-5020 supports various RAID configurations, such as RAID 0, 1, 5, 6, 10, and JBOD. Users may mistakenly set up an inappropriate RAID level or fail to configure redundancy adequately. In case of multiple drive failures or data corruption, improper RAID configuration can lead to data loss.
Neglecting firmware updates: Regularly updating the firmware of the NAS device is crucial for security patches, bug fixes, and performance improvements. Failure to update the firmware can leave the device vulnerable to potential threats or software issues that may result in data loss.
Inadequate network security: Users may overlook the importance of securing their network and NAS device. Weak passwords, open ports, or lack of firewall protection can make the device susceptible to unauthorized access or malware attacks, potentially resulting in data loss.
Accidental file deletion: Users may accidentally delete files or folders from their NAS device without realizing the consequences. If there is no backup or data recovery option in place, such accidental deletions can lead to permanent data loss.

To avoid these mistakes and oversights, it is recommended to regularly back up data, configure RAID properly, keep firmware up to date, implement strong network security measures, and be cautious while handling data on the NAS device.

How to Remove Hard Disks from Your NAS and Connect Them to a PC

Although the NAS VS-5020 can be accessed over the network, you still need to remove its hard disks and connect them directly to a Windows PC. Only then can the recovery software properly scan and analyze the drives. Follow these steps:

Power off the NAS and disconnect it from the power source.

WARNING! Before removing any drives, carefully read the device manual. Improper actions may damage both the NAS enclosure and the hard disks in the RAID array.
Remove the hard disks one by one, gently sliding each drive out of its slot. Remember that hard disks are highly sensitive: any impact or drop can cause serious physical damage.
Label each hard disk according to its position inside the NAS. The order of the drives is crucial for correct RAID reconstruction.
Connect the drives to your computer. In this video, we explain which ports you can use to connect hard disks and what to do if your PC does not have enough free connectors.

Go to view

How to Order Remote Data Recovery

Step-by-Step Data Recovery with Hetman RAID Recovery

This program restores data from damaged RAID arrays and is fully compatible with QNAP VS-5020. Each hard disk in the array contains technical metadata describing how files were written. When launched, Hetman RAID Recovery analyzes this metadata, automatically reconstructs the damaged array, and provides access to its contents. After that, you can browse the recovered disk and save your files. The program can also restore files that were accidentally deleted from the network drive.

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How to recover data from a QNAP

VS-5020 has 5 HDD slots, and it supports the following array types:

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);

How to Safely Recover Data from Disk Images

This utility allows you to create a complete copy of a disk and work with the disk image instead of the physical drive. This approach helps protect your data from:

Overwriting during the recovery process;
Additional data loss caused by bad sectors;
User errors.

To create a disk image, follow these steps:

Ensure you have enough free space to store the image. Its size will typically match the size of the original disk.
In the main window, select the target disk and choose Tools - Save Disk. You can also select multiple disks if needed.
When the Image Creation Wizard opens, select whether you want to save the entire disk or only a specific region. Adjust the settings and click Next.
Choose the directory where the image will be saved. You may select any available disk connected to your PC or upload the image via FTP.

Where Are the User’s Files Actually Stored?

The QNAP VS-5020 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.

RAID Recovery Software: Detailed Comparison

Product	Operating system	RAID controller support	Supported file systems	Virtual RAID controller support	Data recovery from damaged RAID	File preview
Hetman RAID Recovery	Windows, Linux, MacOS	Yes, over 100 controllers	FAT, exFAT, NTFS, ReFS, APFS, HFS+, Ext4, Ext3, Ext2, ReiserFS, Btrfs, VMFS, Hikvision, XFS, UFS, ZFS	Yes	Yes	Yes
DiskInternals RAID Recovery	Windows	Yes, over 10 controllers	FAT, NTFS, Ext2/3/4, HFS+	No	Yes	Yes
R-Studio	Windows, Mac, Linux	Yes, over 20 controllers	FAT, NTFS, Ext2/3/4, HFS+	Yes	Yes	Yes
UFS Explorer RAID Recovery	Windows, Mac, Linux	Yes, over 100 controllers	FAT, NTFS, Ext2/3/4, HFS+	Yes	Yes	Yes
EaseUS Data Recovery	Windows	Yes, over 20 controllers	FAT, NTFS, Ext2/3/4, HFS+	No	Yes	Yes
ReclaiMe Free RAID Recovery	Windows	Yes, over 100 controllers	FAT, NTFS, Ext2/3/4, HFS+	Yes	Yes	Yes

Feedback

We will be happy to answer your questions!

Comments (3)

Hetman Software: Data Recovery 9.08.2022 12:31 #

If you want to ask a question about data recovery, from NAS VS-5020, feel free to leave a comment!

Reply
Drummond Goulding 17.09.2023 14:44 #

Can data recovery from a NAS QNAP VS-5020 device be done if the device is showing signs of overheating or cooling fan failure?

Reply
- Hetman Software 17.09.2023 15:00 #
  
  Yes, it is possible to recover data from a NAS QNAP VS-5020 device even if it is showing signs of overheating or cooling fan failure. However, it is important to address the overheating or fan failure issue first to prevent further damage to the device and the data stored on it.
  If the device is overheating, it is recommended to power it off and allow it to cool down before attempting any data recovery. You may need to replace the cooling fan or clean it if it is clogged with dust.
  Once the overheating or fan failure issue is resolved, you can try accessing the data on the NAS. If the device is still functional, you can connect to it using the appropriate network protocols or access it through the QNAP management interface.
  If the device is no longer functional or the data is not accessible, you may need to consult a professional data recovery service. They have specialized tools and expertise to recover data from faulty NAS devices, even in cases of hardware failure or damage.
  
  Reply

Leave a reply(Hetman Software: Data Recovery).Cancel reply

Updated:
16.10.2025 8:53

Evaluations:
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Author: Vladimir Artiukh, Technical Writer

Vladimir Artiukh is a technical writer for Hetman Software, as well as the voice and face of their English-speaking YouTube channel, Hetman Software: Data Recovery for Windows. He handles tutorials, how-tos, and detailed reviews on how the company’s tools work with all kinds of data storage devices.

Editor: Oleg Afonin, Technical Writer

Oleg Afonin is an expert in mobile forensics, data recovery and computer systems. He often attends large data security conferences, and writes several blogs for such resources as xaker.ru, Elcomsoft and Habr. In addition to his online activities, Oleg’s articles are also published in professional magazines. Also, Oleg Afonin is the co-author of a well-known book, Mobile Forensics - Advanced Investigative Strategies.

Questions and answers

What is SSH and how does it work?
SSH, which stands for Secure Shell, is a cryptographic network protocol used for secure communication and remote administration over an unsecured network. It provides a secure channel for encrypted communication between two devices, typically a client and a server.
Here's how SSH works:
1. Connection Establishment: The client initiates a connection request to the server using the SSH protocol. The server listens on a specific port (usually port 22) for incoming SSH connections.
2. Key Exchange: During the initial connection, the client and server perform a key exchange. This involves negotiating encryption algorithms, generating session keys, and verifying the server's authenticity.
3. User Authentication: Once the key exchange is complete, the client needs to authenticate itself to the server. SSH supports various authentication methods like password-based authentication, public key authentication, and more.
4. Secure Communication: After successful authentication, SSH sets up a secure encrypted channel between the client and server. All subsequent data transmitted over this channel is encrypted to protect it from eavesdropping or tampering.
5. Remote Shell or Command Execution: With the secure connection established, the client can now remotely execute commands on the server or open a remote shell session. The server processes the commands and sends the output back to the client.
SSH also supports other features like file transfer (SCP and SFTP), port forwarding, and tunneling, which allow secure access to services running on remote servers.
Overall, SSH ensures secure communication and remote administration by encrypting data, verifying server authenticity, and providing strong user authentication mechanisms.
How does the NAS QNAP VS-5020 utilize SSH protocol for secure remote access?
The NAS QNAP VS-5020 utilizes the SSH (Secure Shell) protocol for secure remote access by allowing users to establish a secure encrypted connection to the NAS device over a network. Here's how it works:
1. SSH Server: The NAS device acts as an SSH server, running an SSH daemon that listens for incoming SSH connections.
2. Authentication: When a user wants to remotely access the NAS, they initiate an SSH connection using an SSH client. The SSH server on the NAS prompts the user for authentication credentials, typically a username and password.
3. Encryption: Once the user's credentials are provided, the SSH server verifies them and establishes an encrypted session between the client and server. This encryption ensures that the data transmitted over the network cannot be intercepted or tampered with by unauthorized parties.
4. Secure Shell: Once the SSH connection is established, the user gains access to a command-line interface (CLI) on the NAS device. The user can remotely execute commands, manage files, and perform various administrative tasks on the NAS.
5. Secure File Transfer: SSH also enables secure file transfer between the client and the NAS. Users can securely transfer files to and from the NAS using the Secure Copy Protocol (SCP) or the Secure File Transfer Protocol (SFTP), both of which are supported by SSH.
6. Tunneling: SSH also supports tunneling, allowing users to securely access other network services running on the NAS device or behind it. This feature enables secure access to services like web servers, databases, or other applications hosted on the NAS.
Overall, by utilizing the SSH protocol, the NAS QNAP VS-5020 ensures that remote access to the device is secure, encrypted, and protected from unauthorized access or data interception.
What are the advantages and features of SSH in the context of NAS QNAP VS-5020?
The SSH (Secure Shell) protocol provides secure remote access and file transfer capabilities. In the context of a NAS (Network Attached Storage) like the QNAP VS-5020, SSH offers several advantages and features:
1. Secure remote access: SSH allows you to securely access your NAS from a remote location over an encrypted connection. This ensures that your data and credentials are protected from unauthorized access.
2. Encrypted file transfer: With SSH, you can securely transfer files between your local machine and the NAS. The encryption ensures that the data is protected during transit, reducing the risk of interception or tampering.
3. Command-line interface: SSH provides a command-line interface (CLI) to interact with the NAS. This allows for advanced configuration, administration, and troubleshooting tasks that may not be available through a graphical user interface (GUI).
4. Secure remote management: SSH enables secure remote management of the NAS. You can perform various administrative tasks, such as configuring network settings, managing users and permissions, and monitoring system resources, all from a remote location.
5. Customization and automation: SSH allows you to automate tasks on the NAS by running scripts or commands remotely. This can help streamline repetitive tasks and improve efficiency.
6. Compatibility and flexibility: SSH is a widely supported protocol and can be used with various operating systems and devices. It provides flexibility in accessing and managing the NAS from different platforms, including Windows, macOS, and Linux.
7. Two-factor authentication (2FA): Some NAS devices, including QNAP models, support two-factor authentication for SSH access. This adds an extra layer of security by requiring a second authentication factor, such as a time-based one-time password (TOTP) or a hardware token.
It's important to note that enabling SSH on a NAS should be done with caution and proper security measures. Strong passwords, firewall rules, and regular updates should be implemented to ensure the security of your NAS and data.