How to Extract Content from VMDK Files: A Step-By-Step Guide

Sometimes a VM cannot be started, however you may need to access the data stored on a virtual disk used by a VM. This situation can happen after the unsuccessful installation of some applications, updates for an operating system, malware attacks, accidental file deletion, etc. There are a number of methods that allow you to access the content of VMDK virtual disk files. Today’s blog post covers the methods that can be used if a VMDK virtual disk is not encrypted or corrupted. If a VMDK file is encrypted or corrupted, another technique must be applied.

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How the Data is Stored in VMDK Files

VMDK is a virtual machine disk file format, which is the open format developed by VMware. This virtual disk format has the .vmdk extension of files and is used by VMware and VirtualBox virtual machines. However, virtual machines residing on ESXi servers use a slightly different format of vmdk virtual disks – a virtual disk descriptor and virtual disk extent that contains raw data of the virtual disk are two separate files on the ESXi datastore.

The pattern of a virtual disk descriptor name is diskname.vmdk and the pattern of a virtual disk extent name that contains all raw data is diskname-flat.vmdk, accordingly. As for virtual disks of the VMware Workstation format, a virtual disk is represented as a single diskname.vmdk file (monolithic sparse) which is an extent data file that contains an embedded virtual disk descriptor. A virtual disk descriptor defines the structure of the virtual disk, virtual disk geometry, virtual hardware version, and IDs.

A virtual disk descriptor is represented as plain text. On the left side of the screenshot below, you can see a virtual disk descriptor of the ESXi format (a vmdk file that can be opened with any text editor). On the right side of the screenshot, you can set eyes on the data of the virtual disk descriptor that is embedded into a single vmdk file of the VMware Workstation format. The vmdk file is opened in HEX editor.

Comparing a standalone descriptor of the ESXi format and a built-in descriptor of the Workstation format

As you can see, the embedded disk descriptor data is written to the monolithic vmdk file of the Workstation format from the 0x200 address, which is the number of the first byte. If you transform the 200 HEX value to a binary and decimal format, you will get:

200 HEX = 1000000000 Binary = 512 Decimal

This means that if you want to extract the embedded descriptor from the vmdk file, you should extract a portion of data starting from the 512th byte. VMware virtual disk descriptor files were reviewed in the blog post about converting VMware VMs to Hyper-V VMs. Read the abovementioned blog post to see how to extract, edit and import an embedded virtual disk descriptor.

On the screenshot below, have a look at two virtual disk files opened in HEX editor. The same operating system is installed on both virtual disks (the first partition used for installing the OS was created and formatted with a built-in Windows disk utility). On the left side of the screenshot a -flat.vmdk file is displayed (ESXi format). The raw data is written from 0x00000000 on this virtual disk -flat.vmdk file. On the right side of the screenshot, the virtual disk of the Workstation format is displayed and the same data is written from 0x00150000 (byte number 5376) which is not the beginning of the vmdk file.

Storing data in flat vmdk files of the ESXi format and sparse monolithic vmdk files of the Workstation format

Now, after familiarizing yourself with the theory, it’s time to focus on the practical part. Before you proceed, it is recommended that you back up your data to prevent any possible virtual disk damage. Perform operations with your disks at your own responsibility and risk.

Methods That Need Powering on a VM

First, let’s consider the methods of opening virtual disk images by using existing VMs. The advantages of these methods are simplicity and universality. At the same time, however, you need a hypervisor (VMware ESXi, VMware Workstation, VMware Player or Oracle VirtualBox) to be installed on your physical computer.

Using a Live DVD even if an OS on a VM is dead (a legacy method)

The idea behind this method is that you have a VM and can boot from a DVD disc. The ISO disk image can be used as the DVD disc inserted into a virtual DVD drive of the VM. After booting an operating system from a DVD media, you can mount the partitions of your virtual disk and copy files from the virtual disk to a USB hard disk attached to the VM or to your host machine, or to any other machine via the network. Some Live DVD distributions mount disks (partitions) automatically.

This method can be called a legacy method because the principle is similar to copying files from physical disks of physical computers when the installed operating system cannot boot. This method can be used to extract data from VMDK disks of VMs running on VMware ESXi and VMware Player/Workstation.

Be aware that the operating system booted from Live DVD must recognize file systems of partitions of your virtual disk whose files you want to access. For example, Windows cannot work with Linux file systems such as EXT3, EXT4, ReiserFS, etc. by default. Using additional tools on Windows may help to resolve this issue. In turn, modern Linux recognizes Windows file systems such as NTFS and FAT32, hence you can use Linux-based Live DVD discs to copy files stored on virtual disks used by your Windows VM that cannot boot.

Example: Opening VMDK files on ESXi

Let’s consider using this method on an example: when you have a VM with Windows Server 2016 on an ESXi host and the OS on the VM cannot boot, but you need to get the files recorded on the VMDK virtual disk. There are two NTFS partitions on the virtual disk – one is the boot system partition and the second is disk C. The official Ubuntu 18 installation ISO image is used in the current example. The Ubuntu installation media can be used as Live DVD. Upload the ISO image to the datastore that is accessible for the ESXi host on which the VM is residing.

Open VMware vSphere Client, go to Hosts and Clusters, select your VM, and click Edit Settings.

Editing settings of a VM to mount a vmdk file of the dead VM

In the VM settings window, go to CD/DVD drive options. Select the Datastore ISO File option if you have the necessary ISO file on the datastore accessible by the ESXi host. Then, for the CD/DVD Media option, click Browse and select the appropriate ISO file on the datastore. The file name is ubuntu-18.04.1-desktop-amd64.iso in this case.

Inserting a bootable ISO image into a virtual optical drive to boot from DVD and access the contents of the VMDK file

Start the VM, boot from the ISO image and select Try Ubuntu Without Installing. Once Ubuntu has booted from the Live DVD media, open console (Terminal).

Get the root privileges

sudo -i

List available hard disk devices

ls -al /dev/sd*

There are two partitions - /dev/sda1 and /dev/sda2.

Make directories to be used as mount points for each partition.

mkdir /mnt/win-disk1

mkdir /mnt/win-disk2

Mount the partitions of the virtual disk to the appropriate directories.

mount /dev/sda1 /mnt/win-disk1/

mount /dev/sda2 /mnt/win-disk2/

Then list files and directories of the mounted partitions.

ls -al /mnt/win-disk2/

ls -al /mnt/win-disk1/

Accessing files stored inside the VMDK file after booting from Ubuntu live DVD on a VM

As you can see on the screenshot above, the partition mounted to /mnt/win-disk2 is the partition used as disk C: in Windows.

Now you can attach a USB hard disk drive (HDD) to the USB port of your ESXi host and connect this HDD to the virtual machine with the USB pass-through feature for copying the necessary files stored on the VMDK file used as a virtual disk by a virtual machine. Another way is to use an SMB (CIFS) share and copy the contents of the virtual disk (i.e., the VMDK file) to another location via the network. In our example, copying data to the SMB share will be explained. The SMB share has been created on the host whose IP address is, the share name is \\\share, and user10 has write permissions for this share. Don’t forget that Linux, unlike Windows, uses the right slash when connecting to the share.

Let’s mount the SMB (CIFS) share on Linux loaded from the live DVD. First, create a directory to be used as the mount point.

mkdir /mnt/smb-share

Then mount the SMB (CIFS) share to this directory:

mount -t cifs -o user=user10 // /mnt/smb-share

Enter the password of the user.

Now your Linux system is connected to the SMB share, and you can copy the necessary contents stored inside the VMDK file to the SMB share over the network. Let’s go to the directory to which the SMB share is mounted and copy the bootmgr file from the mounted partition of the virtual disk (the VMDK file on the ESXi datastore) to the current directory (SMB share).

cd /mnt/smb-share

cp /mnt/win-disk-2/bootmgr .

Copying files from the mounted VMDK file to the mounted SMB share by using Ubuntu Live DVD on a VM

Then make sure that the necessary files have been copied, and check the contents of your SMB share.

ls -al /mnt/smb-share

As you can see on the screenshot above, the bootmgr file used in this example has been copied successfully. Now you know the first method of copying the contents of the VMDK file to another location when an operating system installed on a VM cannot boot. The logics of using this method on VMware Player or VMware Workstation is the same.

How to mount a VMDK file as a virtual disk to a healthy VM (ESXi/Workstation/Player)

This method is similar to the previous one, but a VMDK virtual disk should be attached to an existing virtual machine that has a functioning operating system. You can attach a VMDK file as an additional virtual disk to an existing VM running on an ESXi host, VMware Workstation and VMware Player. If you want to open a VMDK file of the ESXi VM on VMware Workstation or Player, you should copy both the virtual disk and its descriptor (vmdk and -flat.vmdk files) to a physical disk that is accessible for your computer where VMware Workstation or Player is installed. If snapshots have been taken for the VM, and changes have been made with VM disks after that, don’t forget to copy the VMDK files of delta (differencing) virtual disks in addition to the parent VMDK files.

Let’s consider two examples – how to open a VMDK virtual disk of one VM by using another VM on an ESXi host (both are registered on an ESXi host) and how to extract content from a VMDK virtual disk of an ESXi VM by attaching the virtual disk to a VM of the VMware Workstation format.

Keep in mind that the functioning operating system on the first (healthy) VM must be compatible with file systems used on a virtual disk of the second VM that has a non-bootable operating system (a VM whose VMDK file you want to attach as an additional virtual disk to extract files).

Example 1: Mounting a virtual disk to a VM running on ESXi

Power off the VM that uses a virtual disk from which files you want to extract. Find this virtual disk in the ESXi datastore. Copy the virtual disk to another directory on the same datastore or another datastore to prevent an error caused by virtual disk lock. In our example, we will show how to open a VMDK file whose name is Win-test2.vmdk (this is a virtual disk of the Win-test2 Windows virtual machine in our case). The ESXi host is managed by vCenter. If you use a standalone ESXi host without vCenter, you can use the logics explained in this example – the differences are only in the user interface.

Open VMware vSphere Client, go to Storage and select the datastore on which the necessary VMDK file is located. Select the VMDK file and click Copy to.

Note: If you have a standalone ESXi host and don’t have vCenter, open VMware Host Client by entering the IP address of your ESXi host in the web browser, then go to Storage > [Your datastore name] > Datastore Browser, select your VMDK file and hit Copy. Select destination and hit the Copy button to confirm. Remember, that virtual disks are displayed as VMDK files in the web interface of VMware vSphere Client and VMware Host Client, but a virtual disk consists of the -flat.vmdk and vmdk files (a virtual disk and its descriptor). You can also open the ESXi console directly on the server or by connecting via SSH to copy the files.

Copying virtual disk and descriptor vmdk files on the ESXi datastore

In the opened window, select the destination. You can copy the VMDK file to some location on the same datastore or to another datastore. Let’s copy the VMDK file to the root directory of the same datastore for this demonstration. Both vmdk and -flat.vmdk files are copied in this case.

Selecting destination to copy vmdk files

Now you need to attach the VMDK virtual disk to another healthy VM whose operating system is working properly. In this example, a VM running Windows Server 2016 on the same ESXi host is used (the VM name is WinServer2016). A virtual disk can be attached to this healthy VM while the VM is running. In vSphere Client, go to Hosts and Clusters, select the healthy VM, right click the VM and hit Edit Settings.

Editing settings of the healthy VM for opening a virtual disk copy of the dead VM

In the window that appears, hit Add New Device and select Existing Hard Disk.

Adding a virtual disk to the healthy VM in vCenter

Select the copy of your VMDK file that you have made previously. In the current example, the copy of Win-test2.vmdk located in the root directory of the datastore has been selected.

Opening a vmdk file by attaching a virtual disk to the ESXi VM

Power on the healthy VM to which you have attached the virtual disk you are interested in, if the VM has not been powered on yet. A virtual disk is added on the fly for a running Windows Server 2016 VM. In the guest Windows OS, go to Computer Management > Disk Management (or run diskmgmt.msc in the command line) and find your virtual disk attached. By default, the new attached disk is offline. Right click the disk and hit Online. A disk letter should be assigned automatically for partitions on the added disk. If a disk letter has not been assigned for a partition, right click the partition and hit Change Drive Letter and Paths.

A virtual disk is attached to the healthy Windows VM and a partition is mounted successfully

Now you have full (read/write) access to files and directories of the VMDK virtual disk. Just open the mounted disk in Windows Explorer and copy the necessary content of the VMDK file mounted to the healthy VM. You can also delete unnecessary data from the attached VMDK virtual disk (for instance, if there are any files that were created by viruses), but be careful and don’t harm a virtual disk if there are related snapshots for the mounted VMDK disk.

Viewing content of the vmdk file in Windows Explorer

Example 2: Mounting a virtual disk to a VM running on VMware Player or Workstation

This example is similar to the previous one, but a VM running on VMware Workstation is used to open VMDK files of the ESXi VM. This method can be used when there is no free disk space on the ESXi datastore to copy a virtual disk, for example. A virtual disk of the Win-test2 VM that was mentioned in the previous example will be mounted to a VMware Workstation VM to extract its content.

In VMware vSphere Client, go to Storage > [Your datastore name] > Files, select your VMDK file and hit Download.

As you recall, a virtual disk of the ESXi format consists of vmdk and -flat.vmdk files. You need to download both files to your machine where VMware Workstation or VMware Player is installed. When you download a virtual disk from the ESXi datastore with VMware HTML5 vSphere Client, these two files are packed into a one zip archive.

As an alternative, you can enable SSH access to your ESXi host, go to the datastore directory and copy both virtual disk files to your computer manually by using an SCP client, for instance, WinSCP.

Be aware that when you download a thin provisioned virtual disk from an ESXi datastore that has the VMFS file system to your computer, you will get a lightweight vmdk file and a -flat.vmdk file whose size will be equal to the maximum provisioned size of the virtual disk (as you would do when downloading a thick provisioned virtual disk). This is because thin provisioning can be considered as a VMFS file system feature.

Downloading vmdk virtual disk and descriptor file to open vmdk files in VMware Workstation

Now you can see two files of the ESXi-format virtual disk that have been downloaded in a ZIP archive. The size of the thin provisioned virtual disk on the VMFS datastore is about 2GB now (see the screenshot above) and the size of the same disk downloaded to a workstation machine is about 8GB (see the screenshot below). Unzip the two files from the archive. By default, the files are extracted to the Win-test2.vmdk directory whose name is the same as the archive name without a file extension.

A downloaded zip archive that contains a virtual disk and descriptor vmdk files

For performing the next step, you should have a healthy VM with a functional operating system on your machine with VMware Workstation of Player installed. While in the previous example, the VM running Windows Server 2016 was used, a healthy VM running Windows Server 2008 is used in the current example.

Open VMware Workstation or VMware Player, select your healthy VM and edit virtual machine settings.

Editing VM settings in VMware Workstation to open vmdk files of the ESXi format

In the Hardware tab, hit the Add button.

Adding a virtual disk of the ESXi format to a healthy VM in VMware Workstation

The Add Hardware Wizard is open. Select Hard disk as the hardware type. Then, select a type of disk (you may leave the recommended value). On the Select a Disk screen, select the Use an existing virtual disk option.

How to attach a vmdk file to a VM in VMware Workstation

Select the vmdk file (not -flat.vmdk) you have extracted from the ZIP archive. You can browse the file or enter the entire path to the file manually.

Selecting the VMDK file which is a descriptor of the virtual disk of the ESXi format to add the virtual disk to a VM.

In the current example, ESXi 6.5 and VMware Workstation 15 are being used. The VMware Workstation VM running Windows Server 2008 in our example has the Workstation 12 hardware version (VM version 12). The ESXi VM whose virtual disk we want to attach has the VM version 7.

VMware Workstation says that the virtual disk copied from the ESXi host is not compatible with this virtual machine:

The selected virtual disk is incompatible with this Workstation 12.x virtual machine. Adding this disk would make this virtual machine incompatible with older VMware products.

A compatibility issue may occur when opening VMDK files of the ESXi format in VMware Workstation

This error can be fixed by editing the disk descriptor file (the lightweight vmdk file in the case of virtual disks of ESXi VMs). Open your VMDK file in the text editor and edit the number in the Ddb.virtualHWVersion string. In our case, 13 gets changed to 12.

Note: Remember that for virtual disks of VMware Workstation VMs, a virtual disk descriptor is built in the virtual disk VMDK file (there is no separate descriptor file as for virtual disks of ESXi VMs).

Editing a virtual disk descriptor vmdk file for opening a flat-vmdk file in VMware Workstation

After this manipulation, the virtual disk has been successfully added to the existing VM.

Power on the VM if it has not been powered on yet

Open the Disk Management in Windows, change your virtual disk status to online, assign a drive letter to a partition and browse the files.

A vmdk virtual disk of the ESX format has been attached to a Windows VM on VMware Workstation

Methods that Don’t Need Powering on a VM

The methods that don’t require you to configure and power on a virtual machine have their own advantages. Some of these methods don’t require installing a hypervisor. You can mount VMDK files directly to your host operating system in a short period of time.

Mounting VMDK files in a host OS with VMware Workstation

This method requires you to have VMware Workstation installed on a Windows or Linux operating system running on your physical computer. VMware Workstation provides a nice feature that allows you to mount VMDK files to your host operating system. Virtual disks of the ESXi format and delta disks related to VM snapshots are supported. Similarly to all previous methods considered in this blog post, your operating system must support file systems of virtual disk partitions.

If you have snapshots of your virtual machine, the delta virtual disks are created after creating each snapshot. You should have a parent virtual disk and delta disks available if you want to open a virtual disk state the moment after taking one or another snapshot. In this case, you should mount the appropriate delta virtual disk to your host operating system. Dependencies related to the parent virtual disk will be resolved automatically.

If you have snapshots but wish to open a parent virtual disk, please open the parent virtual disk in the read-only mode because making changes on the parent virtual disk can cause problems with damaging snapshots or linked clones created from a parent virtual machine with the parent virtual disk. The read-only mode prevents you from writing data on a virtual disk after mounting the disk to the host OS. You can mount VMDK virtual disk files if a VM that uses this virtual disk is powered off, or if a particular VM isn’t using this virtual disk.

Let’s consider how to mount a VMDK virtual disk of the VMware Workstation VM that has snapshots. There is Windows installed on one NTFS partition on a virtual disk of the VM. After taking the first snapshot, the Snapshot1.txt file was created in the root directory of the disk C: and, similarly, after taking the second snapshot, the Snapshot2.txt file was created there. The first example is for Linux and the second example is for Windows. Virtual disk files of the old Windows XP VM are used in the current example.

Example 1: Mounting VMDK on the Linux host

Open VMware Workstation for Linux and go to File > Mount Virtual Disks.

Mounting a VMDK file using VMware Workstation on the Linux host

Hit Mount Disk, the pop-up window is opened after that. Click Browse and select the virtual disk VMDK file.

Mounting a VMDK file as a virtual disk to a Linux host machine by using VMware Workstation

Let’s select the VMDK file of the second differential virtual disk created after taking the second VM snapshot. The name of this file appears as VM_name-000002.vmdk in such cases (WinXP-test-000002.vmdk is used in this example).

Selecting a vmdk file to mount as a virtual disk on the Linux host

Create the directory on your Linux file system for mounting a virtual disk of the VMDK format to that directory. Let’s create the /mnt/vmdk/ directory in the Linux console.

mkdir /mnt/vmdk/

Set permissions for your user (the user name is user1 and it is a member of group1 in the current example):

chown -R user1:group1 /mnt/vmdk/

chmod -R 0775 /mnt/vmdk/

Now, select the directory you have created as the target directory, check the “Mount in read-only mode” checkbox and click Mount.

Everything is ready to mount a VMDK virtual disk on the Linux host machine

Now you are able open the /mnt/vmdk/ directory in your Linux file explorer and browse files and directories located on the VMDK virtual disk. You can see Snapshot1.txt and Snapshot2.txt files which were created after creating the first and second snapshots in this example. Each of these two files is located on the separate delta VMDK virtual disk.

Viewing the content of the vmdk file after mounting the image to the directory on the Linux host machine.

Don’t forget to unmount the VMDK virtual disk from the directory (mount point) on your host Linux system after finishing operations with the virtual disk content.

Unmount the vmdk image file from your host Linux file system when not in use

Mounting VMDK on the Linux host in console

If you prefer using the console interface, you can mount VMDK disk images with this command:

vmware-mount /media/user1/vms/vm_name/vm_disk_name-000002.vmdk /mnt/vmdk


vm_name is the name of the virtual machine that is the same as the VM directory name in this case. WinXP-test is the VM name in our example.

vm_disk_name is the name of the virtual disk (WinXP-test.vmdk is used in this example)

vm_disk_name-000001.vmdk is the name of the first delta (differencing) disk created after taking the first VM snapshot (WinXP-test-000001.vmdk in this case)

vm_disk_name-000002.vmdk is the name of the second delta disk created after taking the second VM snapshot accordingly (WinXP-test-000002.vmdk in this case)

Mount a virtual disk. By default, the virtual disk is mounted in the read/write mode. You can use the -r key in the command line to mount a disk in read-only mode.

vmware-mount /media/user1/vms/vm_name/vm_disk_name-000002.vmdk /mnt/vmdk

List all mounted VMDK virtual disks:

vmware-mount -L

Before finishing working with mounted VMDK virtual disks, unmount all virtual disks:

vmware-mount -x

Example 2: How to mount VMDK on the Windows host

The idea of how to mount VMDK files in Windows is similar. In addition to the File > Map Virtual Disks option in the graphical user interface (GUI) of VMware Workstation, you can just right click the VMDK file in Windows Explorer and in the context menu, hit the Map Virtual Disk option. Let’s mount the VMDK file of the first differential virtual disk created after taking the first VM snapshot. The name of this VMDK file has the following format: VM_name-000001.vmdk (WinXP-test-000001.vmdk is opened in this tutorial).

An easy method to map a vmdk virtual disk in Windows with VMware Workstation

It is recommended that you open the VMDK file in read-only mode to prevent any possible damage of virtual disks that belong to the snapshot chain after writing data. The default drive letter is Z: in this case and the drive is opened in Windows Explorer automatically after mapping if the appropriate checkbox is ticked. Hit OK to proceed.

Mapping a virtual disk (vmdk file) in Windows with VMware Workstation

Now the virtual disk is mounted as disk Z: in Windows. On the screenshot below, you can see the Snapshot1.txt file created after taking the first snapshot. The Snapshot2.txt file is missing because it was created after taking the second VM snapshot, and we have opened a delta virtual disk related to the first VM snapshot.

Viewing the content of the virtual disk image (vmdk file) in Windows Explorer

When you have finished working with the mapped VMDK virtual disk, don’t forget to disconnect the disk. Right click the appropriate VMDK file and hit Disconnect Virtual Disk. After disconnecting the virtual disk, you can power on a VM that uses this virtual disk.

Disconnecting a virtual disk (vmdk file) from a Windows host OS

Using 7-zip to extract content from VMDK files

If you are looking for how to open VMDK files without running virtual machines, you can install 7-zip and extract content from virtual disk images. 7-zip is a free tool intended to archive files and unpack files from archives and other images. This tool can be used on Linux and Windows machines.

7-zip can open vmdk and -flat.vmdk files (this utility can open a single -flat.vmdk file if the descriptor vmdk file is missing) – it is actually for virtual disks of the ESXi format. 7-zip cannot open delta VMDK files created after taking VM snapshots.

How to open VMDK files with 7-zip on Linux

Install a full pack of 7-zip on your Linux machine. Ubuntu is used in this example.

apt-get install p7zip-full

List contents of the vmdk file with 7zip

7z l vm_name.vmdk

Let’s find the files that contain “boot.” in their names, for instance.

7z l /media/user1/vms/WinXP-test/WinXP-test.vmdk | grep boot[.]

Where user1 is the name of our Linux user, l – list.

Using 7-zip to extract content from a vmdk file in Linux

Let’s extract (e) the boot.ini file from the VMDK image:

7z e /media/user1/vms/WinXP-test/WinXP-test.vmdk boot.ini

Extract other files and directories from the VMDK file similarly.

How to open VMDK files with 7-zip on Windows

Download the compatible version of 7-zip from the official web site and install the application on your Windows machine. Use the EXE installer for more convenience. After installing 7-zip on Windows, new 7-zip options are added to the context menu when you right click any file or folder in Windows Explorer (see the screenshot). Use these options to open a VMDK file as an archive or extract files right now.

Using 7-zip to extract content from the vmdk file in Windows

On the screenshot below, the content of the standalone Win-test2-flat.vmdk file is displayed in the GUI of 7-zip used in Windows.

Viewing content of the virtual disk (flat vmdk file) by using 7-zip in Windows

Other Methods to Open VMDK Files in Linux

One of the most powerful capabilities of Linux is the ability to perform the highest number of operations in the console even with built-in tools. These tools will help you to mount VMDK files and access the content stored on virtual disks. Ubuntu Linux is used in the provided examples.

How to mount VMDK files by using /dev/loop

Loop devices are pseudo-devices in Linux that make files accessible as block devices and can be used to mount disk images that contain file systems. Loop devices are named as /dev/loopX where X is the number of the loop device. This method is good to mount -flat.vmdk files even without a virtual disk descriptor.

Let’s explore how to mount a VMDK file in Linux to access the files of the virtual disk as an example. There is a virtual disk of the ESXi format that contains one partition; a descriptor file is missing. A long time ago, Windows XP was installed on that virtual disk.

  1. Use one of the two commands to check the number of existing loop devices on your Linux system.

fdisk -l | grep /dev/loop

df -h | grep /dev/loop

  1. In our case, devices with numbers 1 to 21 already exist (/dev/loop1 - /dev/loop21). Thus, let’s create the loop device number 30 – this number is free. We will associate this device with the -flat.vmdk file.

losetup /dev/loop30 /vms/Win-test2-flat.vmdk

  1. Set the offset:

losetup -o 32256 /dev/loop31 /dev/loop30

Where 32256 is the offset that is 63*512 for a disk formatted in Windows XP/Server 2003 and older Windows versions (63 is the number of the first sector of the partition and 512 bytes is the sector size). For Windows 7/Server 2008 and newer Windows versions, try the offset 105906176.

You can retrieve information about the sector size, and the first sector used for the boot start with the command:

fdisk -l /dev/loop30 /vms/Win-test2-flat.vmdk

Retrieving information about the sector size

As an alternative, for virtual disks that contains multiple partitions, you can use parted to determine the start and the end of each partition:

parted /dev/loop30

In the parted console, enter the following commands.




Checking information about a vmdk virtual disk and its partitions

  1. Create a directory to be used as the mount point for the VMDK image:

mkdir /mnt/vmdk-image

  1. Mount the loopback device associated with the VMDK image to the created directory:

mount /dev/loop31 /mnt/vmdk-image

  1. List the content of the mounted image:

ls -al /mnt/vmdk-image

  1. After finishing working with the content of the virtual disk, unmount the image and disconnect the loop device.

umount /mnt/vmdk-image

losetup -d /dev/loop31

Using a loopback pseudo-device to mount vmdk virtual disk images in Linux

How to mount VMDK files with kpartx

Kpartx is a tool that can mount partitions within image files to the directories of your real Linux file system. This tool can be used to set up device mappings for partitions of block devices. This method is also nice for mounting -flat.vmdk images used on ESXi servers. Let’s see how to mount the -flat.vmdk file used in the previous example.

  1. Install kpartx:

apt-get install kpartx

  1. Add the partition mapping for the VMDK image in the verbose operating mode:

kpartx -av /vms/Win-test2-flat.vmdk

  1. Mount a partition to the /mnt/vmdk-image directory prepared before:

mount /dev/mapper/loop30p1 /mnt/vmdk-image/

Where loop30 is the number of the loop device and p1 is the number of the partition inside the image (the first partition on the disk image).

  1. List the content of the virtual disk partition you have mounted:

ls -al /mnt/vmdk-image/

Using kpartx to mount vmdk images in Linux

  1. When you have finished operations with files of the VMDK image, unmount the VMDK virtual disk image.

umount /mnt/vmdk-image

kpartx -d /vms/Win-test2-flat.vmdk


Today’s blog post has covered different methods of getting data from VMDK files which are usually used as virtual disks. VMDK files can be opened with or without powering on a VM, and can also be mounted in Linux and Windows as virtual disk images. Hopefully, this information will help you find a suitable method for resolving your tasks.

Understanding how to open vmdk files and extract content from VMDK files is important if something goes wrong with a virtual machine. Knowing multiple methods of extracting VMDK content gives you the power of choice because the different methods can each be the best option in certain situations. Moreover, it is even better to have backups of your VMs in addition to that knowledge.

NAKIVO Backup & Replication can back up and restore VMs running in VMware vSphere in the best way. With VMware backups from NAKIVO, you can recover the entire VM, the particular virtual disk or separate files from backup to a custom location by using Universal Object Recovery, Instant File Recovery to Source, Flash VM Boot, and other features.

The product can be installed on Linux, Windows and different supported NAS devices. Download NAKIVO Backup & Replication today and try the product in your own environment.

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