Recovery of Proxmox VE Virtual Machine Data from RAW, VMDK, and QCOW2 Disks

• Author:
  
  Vladimir Artiukh
• Editor:
  
  Oleg Afonin
• Updated: 27.07.2026 20:50

This article examines the process of data recovery from virtual machine disks in RAW, VMDK, and QCOW2 formats, as well as from Directory storage based on the Ext4 file system, created in Proxmox Virtual Environment 9.1.1. We will analyze the most common data loss scenarios: accidental deletion of files inside a virtual machine or of the virtual machine itself, data corruption caused by drive failure, server, PC, or NAS malfunctions, as well as software failures in Proxmox VE caused by updates, critical errors, or removal of the operating system.

Contents

• KVM/QEMU Capabilities
• STEP 1. How to connect server drives to a PC?
• STEP 2. Recovering Directory Ext4
• STEP 3. Mounting disk images
• STEP 4. Recovering data from an image
• STEP 5. Recovering deleted virtual machines
• Conclusion
• Questions and answers
• Comments

Proxmox VE is one of the most popular server virtualization platforms, widely used in both enterprise environments and home labs. It allows users to create and manage virtual machines using various disk formats, including RAW, VMDK, and QCOW2. Despite the platform’s high reliability, accidental deletion of a virtual machine, storage formatting, file system corruption, or hardware failure can lead to the loss of important data.

In most cases, this does not mean that the information is lost permanently. If no intensive write operations were performed on the storage after deletion or failure, there is a high probability of successful recovery of virtual machine files. The key is to stop any write activity as soon as possible and use specialized software to analyze the disk and search for lost data.

In this article, we will look at how to recover Proxmox VE virtual machines stored in RAW, VMDK, and QCOW2 formats. You will learn in which cases recovery is possible, what characteristics different virtual disk formats have, and we will also review the recovery process step by step using Hetman Partition Recovery. Particular attention will be given to data loss scenarios caused by deletion, formatting, file system corruption, and drive failures.

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How to Recover Data from Proxmox: LVM, VM Disks, Ext4, and XFS

KVM/QEMU Capabilities

KVM and QEMU work together as a powerful tandem, creating one of the most efficient virtualization solutions.

• KVM integrates directly into the Linux kernel, turning it into a hypervisor. This allows virtual machines to interact directly with Intel VT-x or AMD-V hardware extensions and operate at performance levels close to physical servers.
• QEMU acts as an emulator that provides the virtual machine with the necessary hardware: network adapters, video adapters, disk controllers, and USB ports. Using optimized VirtIO drivers enables the system to run much faster while providing the guest operating system with a full-featured environment.

One of the main advantages of this combination is exceptional storage flexibility.

QEMU supports the advanced QCOW2 virtual disk format, which allows thin provisioning and encryption. In addition, the system supports formats from other platforms, including RAW, VMDK, and VDI, making KVM and QEMU a convenient solution for migrating virtual machines from other ecosystems without lengthy file conversion.

At the level of professional solutions, this tandem provides access to powerful functionality. It supports Live Migration, which makes it possible to move a running virtual machine between physical servers without losing connectivity or rebooting.

Another critically important capability is PCI Passthrough. This technology allows a real physical GPU or network adapter to be passed directly to the guest operating system, providing full device performance for complex computations, rendering, or other resource-intensive tasks.

STEP 1. How to connect server drives to a PC?

Before starting software recovery, you need to connect the server drives to the PC correctly. This can be done in several ways:

• The most reliable option is a classic SATA connection directly to the motherboard. This ensures maximum read speed and minimal latency.
• If the board does not have enough connectors for the entire array, you can use a PCIe-to-SATA adapter to connect additional drives.
• If you do not want to open the PC case, you can use external USB docking stations or adapters.

Note: scanning speed over USB will be significantly lower, which will noticeably affect the time required to work with large data arrays.

And the most important rule: always consider creating a disk image. This is especially important if the drives have bad sectors, make unusual noises, or there is a risk of further degradation. In this case, the software will work with a virtual copy without putting additional load on the damaged physical drive.

STEP 2. Recovering Directory Ext4

Among all storage types in Proxmox, the Directory option based on Ext4 is the easiest to understand. Its main feature is that it uses a standard folder hierarchy rather than complex block devices such as ZFS or LVM-Thin.

In practice, it is a regular file system where QCOW2 or RAW virtual disks, bootable ISOs, and backups are stored as ordinary files in a familiar directory. Thanks to this transparent structure, this storage type is максимально user-friendly.

Imagine a situation in which, due to a server hardware failure or a hypervisor software error, the structure of such storage has been damaged, or an important folder was accidentally deleted. Despite the fact that this is server infrastructure, the data recovery process here follows a classic and straightforward algorithm thanks to the simple file architecture.

Let us consider the recovery procedure in the event of a server hardware or software failure:

• Hardware failure most often occurs due to a motherboard failure, controller malfunction, or power issues, when the server stops booting even though the drives themselves remain physically intact.
• Software failure usually occurs as a result of an unsuccessful Proxmox update, corruption of system libraries, or accidental deletion of hypervisor configuration files.

In both cases, the consequences are the same: the system refuses to boot, the management web interface becomes unavailable, access to virtual machines is completely blocked, and you are left with data on the drives without the ability to start them normally.

To solve this problem, we will use Hetman Partition Recovery. The program recognizes Linux partition structures, performs a deep scan of the drives, and restores the original directory tree.

To find the lost data, select the automatically identified logical volume labeled Ext4 in the program and start the scan.

To begin with, we recommend using Fast scan. If the file system structure is severely damaged and the quick search does not produce results, use Full scan.

When the program finishes, open the found Directory storage. You will see the original Ext4 file system folder structure. Since this case involves virtual machine files stored on the disk, find them in the Ext Partition section, go to the Images folder, and open the 100 directory.

Select the required virtual machine images, click Recovery, and specify the path to save them on a safe working drive. Make sure in advance that there is enough free space on it.

STEP 3. Mounting disk images

The RAW format is the simplest type of virtual disk, consisting of an exact byte-for-byte copy of the data. It immediately reserves the entire allocated space on the server drive regardless of actual usage. Due to the absence of complex internal structure and compression, this format provides maximum speed and is also the most convenient object for recovery algorithms, which scan it like a regular physical disk.

The QCOW2 format is a modern solution for the QEMU environment that uses dynamic disk allocation. Such a disk grows physically only as new files are written by the guest system. It supports snapshots and encryption, but its multi-layer architecture requires deep analysis of allocation tables by recovery tools after a hypervisor failure.

The VMDK format was created for the VMware ecosystem, but thanks to its universality it is supported in Proxmox and is often used after migrating virtual machines from other server platforms. It allows flexible disk size management and has an open structure, which enables recovery software to mount such images and extract files without starting the virtual machine itself.

After a successful scan of the Ext4 Directory storage, the program will display all found virtual machine files. To begin working with their contents, select the required images, click Recovery, and specify a safe location to export these files to the computer.

When the saving process is complete, you can proceed to step-by-step mounting of disk images in Hetman Partition Recovery.

Mounting VMDK and QCOW2 formats follows the same procedure. On the toolbar, click Mount Disk. In the Disk image type window, select VMware Workstation to work with the VMDK file.

In the next Select folder window, specify the path to the folder where you saved the virtual disk. The program will automatically analyze the specified directory and display the found image in the Virtual machine images section.

Select it from the list, and the mounted disk will appear on the main screen, fully ready for data search.

To mount a QCOW2 image, the procedure is similar. In the Mount Disk window, select QEMU in the Disk image type section, then specify the path to the folder where the file is stored.

For the RAW format, the mounting procedure is slightly different. In the Mount Disk window, find the Standard disk images field and select RAW disk images.

After that, in the search window, select the saved virtual machine file directly. The program will mount it and display it on the main screen, preparing the disk for scanning and recovery of lost files.

STEP 4. Recovering data from an image

In this example, we will demonstrate the process of recovering data from an already mounted QCOW2 image. Select this virtual disk on the program’s main screen and start the analysis.

To begin with, we recommend using Fast scan. It will quickly analyze the image contents and display the results on the screen. If the file system structure is severely damaged and the quick search does not produce the required results, use Full scan.

When the scan is complete, open the found storage. The program will reconstruct the original directory structure, displaying both existing and previously deleted data.

Find the required folder with the files, select them, click Recovery, and specify the path for saving them to another safe working drive.

STEP 5. Recovering deleted virtual machines

In Proxmox, a virtual machine is most often deleted due to human error, which leads to the immediate disappearance of configuration files and virtual disks in RAW, VMDK, or QCOW2 formats, since the system has no recycle bin.

However, the data is not physically overwritten: the file system only removes its records from the allocation table, marking the space as free. Therefore, the key rule for successful recovery is to immediately stop any writes to the storage to avoid overwriting residual data, and to begin the software recovery procedure as soon as possible.

To solve this problem, we will use Hetman Partition Recovery.

After connecting the drive, the program will automatically detect the Ext4 logical partition where the deleted virtual machine files were stored.

Select this partition and start Fast scan. After the quick search completes successfully, the program will display the original directory structure.

If the required files are not found visually, use the search tool and specify their exact name or size.

Select the required virtual disk images, click Recovery, and specify the path for saving them to a safe working drive. Make sure in advance that there is enough free space on it.

Conclusion

Loss of a virtual machine in Proxmox VE does not always mean loss of data. In most cases, RAW, VMDK, and QCOW2 virtual disk files can be successfully recovered even after accidental deletion, storage formatting, file system corruption, or hardware failure. The speed of response is critical: once data loss is detected, any write activity to the drive must be stopped immediately to avoid overwriting information.

Each virtual disk format has its own characteristics: RAW provides maximum performance and the simplest structure, VMDK is widely used in VMware products and compatible with many platforms, and QCOW2 offers advanced capabilities, including snapshots, compression, encryption, and dynamic storage allocation. Despite these differences, modern data recovery tools can work with all of these formats.

Using specialized software such as Hetman Partition Recovery makes it possible to find lost virtual machine files, restore the directory structure, and regain access to data even in complex cases. However, the best way to protect against data loss remains regular backups of Proxmox VE virtual machines and storage. Combining a reliable backup strategy with prompt recovery significantly reduces the risk of downtime and loss of critical data.