The many benefits of virtualization software have led to an increase in its use among businesses the world over. Also, this demand has fueled different vendors to offer virtualization software, each in a different format. For example, let’s take the two largest players in this industry — Microsoft and VMware. Both these companies offer excellent virtualization software, but unfortunately they’re not compatible with each other. VMware uses a format called virtual machine disk (VMDK) while Microsoft uses a format called virtual hard disk (VHD) to store your virtual disks. So, what happens when you have a client who gives you a bunch of VMDK files, but you have a Hyper-V set up in your system? Well, you’ll have to convert one format to another, meaning you’ll need some sort of VMDK to VHD conversion tool.
That’s easier said than done simply because the conversion process is complex, to say the least. This is why you need a tool that’ll automate this conversion for you so you can simply focus on the tasks on hand.
Before going into the different tools, let’s briefly look at what each of these formats are.
As you might have guessed by now, VMDK was originally created by VMware for its virtual appliance products, but today, it is in open format. In fact, it is one of the most popular disk formats in Open Virtualization Format that’s used for a ton of virtual appliances.
Files that end with .vmdk store the entire content of your hard drive. They can be used as a regular hard drive to store information or even as a backup for critical data. But you may not be able to store all your contents in the same file, as the maximum size of .vmdk files for most applications is 2TB. Probably, the only exception is VMware vSphere 5.5 that has a 62TB capacity.
Many VMware products use VMDK as the native file format. Some of them are:
- VMware workstation
- VMware ESX
- VMware ESXi
- VMware server
- VMware fusion
- VMware player
Besides VMware’s products, there are also a few other third party products that use VMDK, and they are:
- Sun xVM
- Norton GHOST
- Parallels desktop
- SUSE studios
Virtual hard disk, or VHD in short, was first created by a company called Connectix for its virtualization software. Microsoft acquired this company in 2003 and since then it has been under Microsoft’s ambit.
In 2005, Microsoft made this format available to third parties under its Microsoft Open Specification Promise, and this has helped individuals and users make the most of this virtual disk file format.
This is the default format for Hyper-V that’s available in Windows 7, Windows Server 2008, virtual server, and Windows virtual PC.
Now that we have a good idea of both these formats, let’s look at the tools that help to convert vmdk to vhd.
VMDK to VHD conversion tools: Microsoft virtual machine converter 3.0
Microsoft has come up with a conversion tool called Microsoft virtual machine converter (MVMC) to convert VMware disks and virtual machines to Hyper-V and Windows Azure hosts. With this converter, you can convert not just VMDK to VHD format, but also physical machines and disks to Hyper-V hosts.
In addition to converting to VMDK to VHD format, you can add virtual network adapters and convert virtual machines from VMware vSphere 5.5, vSphere 5.1, and vSphere 4.1 to Hyper-V. A wizard-driven GUI makes all these conversions a breeze.
However, there are some prerequisites for using this tool, and they are:
- Windows server 2008 R2 SP1, Windows server 2012, and Windows server 2012 R2 are the only operating systems that support this tool.
- You need Microsoft .NET framework 3.5 and .NET framework 4 to install this tool on Windows server 2008 R2 SP1.
- You need Feature bits compact server and Visual C++ redistributable for this tool to work.
Once your requirements are in place, download this tool from the Microsoft download center and run the MSI file. This should install the tool for you.
For starting the conversion process, use the different PowerShell cmdlets that come with the kit.
StarWind V2V converter
Another good conversion tool is the V2V converter from StarWind. This tool converts to and from most commonly used file formats such as VMDK, VHD, VHDX, and QCOW. As a result, it offers the highest flexibility for IT professionals who have to work across different virtual file formats.
Additionally, this tool makes it easy to migrate across different hardware environments during the conversion to VHDX mode. The biggest advantage is that the virtual machine automatically adapts to the new hardware, thereby reducing compatibility issues.
2Tware convert VHD
2Tware convert VHD is a great tool to convert a virtual machine hosted on the local desktop to a VHD format. This is a fairly simple and easy-to-use application that converts VMDK to VHD format. Since this is a sector-by-sector copy operation from one file format to another, the source file remains unchanged.
In addition to converting the format of physical drives, you can also convert existing physical computers into virtual machines through a process called P2V conversion. When you convert your physical computer into a VHD file, you have the flexibility to install and test any software and this won’t affect your physical system.
Vmdk2vhd is another free tool that converts files in VMDK format to VHD. This tools requires Microsoft .NET 2.0 or later versions to work. The installation process is fairly simple, as you just have to unzip the folder and run a file called vmdk2vhd.exe.
Unfortunately, this tool is not available for Linux operating systems.
WinImage is a good choice if you’re using old versions of Windows operating system, especially Windows for 95/98, and Windows NT/2000/XP/2003.
It comes with many convenient features that give you a lot of flexibility. Here’s a look at some of the things you can do with this software.
- Create empty disk images
- Extract files from a disk image
- Create a disk image from a removable file
- Change a disk image format, from VMDK to VHD
- Defragment a disk
This shareware requires you to register at the end of a trial period of 30 days.
vConverter SC is an enterprise-class software that converts virtual disks from VMDK to VHD formats without altering the source in any way. You don’t even have to reboot or install anything on the source for this conversion.
You also have the choice to automate your time-consuming and error-prone processes such as target VM configuration. This means your conversion time and effort is greatly reduced when you use vConverter SC.
In short, there are many tools available today to convert virtual disks from VMware’s VMDK format to Hyper-V’s VHD format. Out of these, MVMC is the most popular and sought-after tool as it handles many of the complexities of this conversion for you.
However, there are also lesser-known tools like StarWind’s V2V converter and 2T convert VHD that can do this job for you. One word of caution here — make sure to check if the product is still in existence and if there’s a support system available before you install it on your system. Also, check if the installation is available for your version of Windows, as some of these products are available only for earlier versions.
As always, please share your experience in using these tools in the comments section.