Introduction to Digital Exhausting Disk in Home windows

Earlier than you begin

Aims: be taught what’s VHD, why it’s used, and which instruments are used to handle VHDs.

Stipulations: no stipulations.

Key phrases: vhd, file, home windows, disk, system, create, laborious, set up, digital, boot, drive, dimension, connect

What’s VHD

VHD stands for Digital Exhausting Disk. It’s a a format that’s structured to signify a normal laborious disk drive that permits encapsulation of an working system and information right into a single file. That single file helps all normal disk operation. VHD file nonetheless resides on our laborious drive, however all of the content material is written inside VHD. All our partitions, all our information, and the entire file system is saved in a VHD file on our laborious drive which we use besides from. Notice that VHD might however doesn’t have to incorporate an working system and/or information. We will select the identify of our VHD file throughout the configuration course of, however the extension is all the time .vhd. We will create a brand new VHD through the use of the out there disk area on our laborious drive. Then we will put it aside to some location on the disk.


353.1 – Common Set up In comparison with VHD

Newly created VHD is just like an uninitialized laborious disk drive. After we create a VHD, we will create a number of partitions in it and format them utilizing FAT, ExFAT or NTFS file system. Relating to dimension, VHD could be mounted in dimension or it may be dynamically increasing. A hard and fast VHD has a predefined quantity of laborious disk area, which is reserved on the bodily disk. This reservation additionally consists of empty area inside the digital laborious disk. This disk kind of VHD takes longer to create, however the efficiency is best as a result of the whole digital disk is a contiguous block. A dynamically increasing VHD allocates bodily disk area as digital disk storage is utilized by the digital machine. That implies that the dimensions of the .vhd file grows as we use our digital machine. Additionally, dynamically increasing VHD information don’t robotically scale back in dimension when information are deleted. To scale back the dimensions we will use the compact (scale back) motion for the VHD. They will also be expanded (elevated) to the utmost dimension out there in a VHD.

Present VHD could be mounted (hooked up) in order that it shows as a disk in our present working system. We will assign a drive letter to mounted VHDs. We will solely connect a VHD that’s positioned on an NTFS quantity, and we can not connect a VHD that has been compressed by NTFS or encrypted utilizing Encrypting File System (EFS) on the host quantity. We will additionally connect a VHD as read-only disk. That method we will’t modify the contents of VHD. Hooked up VHDs could be indifferent (dismounted), and we should always do this if we plan to repeat it to different location. Indifferent VHDs could be deleted.

Utilization of Digital Exhausting Disks

The nice factor when utilizing VHD information is that we will configure multiboot or dual-boot techniques extra simply. After we configure multiboot utilizing common installations, we must create a brand new partition for our new set up and set up Home windows there. When utilizing VHD information, we merely create a brand new VHD file for our new Home windows set up. That implies that we will have one partition with a number of VHD information (a number of working techniques). If we need to take away an insulation from multiboot setting, it’s easy course of when utilizing VHDs. We merely delete the VHD file of the working system that we need to take away, and all needs to be set.

 Multiboot Environment

353.2 Multiboot Atmosphere

Till now VHD information had been utilized by HyperV, Digital Server and Digital PC as digital disks for working the digital machines as an alternative of them. The VHD format can be utilized by Home windows server backup, Home windows DPM or Knowledge Safety Supervisor and quite a lot of different Microsoft and non-Microsoft software program. Now we will use a VHD file to host a working working system with out utilizing another software program digital machine.

When utilizing VHDs we even have extra flexibility in relation to catastrophe restoration. For instance, we will copy the VHD file from one machine that’s damaged to a different laptop with comparable {hardware}, and boot up from that VHD. The customers may have entry to the identical set up and information as they did on the outdated laptop.

Administration Instruments

To handle VHDs we will use DiskPart, Disk Administration in Home windows,  WIM2VHD and BCDEdit. With Disk Administration MMC snap-in we will create, connect and detach VHDs. With DiskPart we will create, connect, detach, compact, increase and look at particulars about VHD. Widespread diskpart instructions used for VHDs are:

  • create vdisk – creates a brand new VHD, with the dimensions of the VHD file expressed in MB (file identify has to have a .vhd extension)
  • connect vdisk – attaches a VHD
  • detach vdisk – detaches a VHD
  • compact vdisk – reduces the dimensions of a VHD
  • increase vdisk – expands the utmost dimension out there in a VHD
  • element vdisk – shows details about a VHD

The Home windows Automated Set up Equipment (Home windows AIK) has a utility named WIM2VHD which we will use to create a VHD picture from Home windows set up supply. Utilizing WIM2VHD we will create a brand new VHD of a specified kind and dimension, apply a .wim to a VHD, use an Unattend file to automate the Out Of Field expertise portion of Home windows setup the primary time a generalized VHD is booted, and apply updates to VHDs.

We will additionally use deployment instruments to put in a Home windows set up instantly onto a VHD file. This direct set up onto a VHD file can then be maintained and deployed. Additionally, if we have already got a pc working Home windows 7 Enterprise or Final, we will copy the brand new VHD file with new system to our laborious drive, and configure our laptop besides from the brand new VHD through the use of the BCDedit command. BCDEdit is a command-line instrument used to handle BCD shops. Utilizing BCDEdit we will create and modify BCD shops, and add boot menu parameters.


VHDs is not going to degrade or scale back the efficiency of our laptop and working system.

Set up

To put in Home windows 7 to a VHD we will insert the set up media, and choose the Restore your laptop possibility. Then we open the command immediate. If our laborious disk will not be configured sure, we will run DiskPart to partition the drive, assign a drive letter, and format the partition. Then we will use DiskPart once more to create and connect a VHD file contained in the partition. After that we will set up Home windows 7 to the drive that’s the VHD file.

We will use WIM2VHD file to create a VHD picture from any Home windows 7 set up supply. After finishing the set up, the VHD will boot instantly into the Out Of Field Expertise (OOBE) and be prepared for consumer customization. That is just like common Home windows set up. Moreover, WIM2VHD helps using reply information created trough Home windows SIM to carry out an unattended set up. With reply information we will customise the set up earlier than deploying the VHD. WIM2VHD and booting from VHD is simply supported in Home windows 7 Final, Enterprise and Home windows Server 2008R2 editions. All Home windows 7 variations permit us to create and connect digital disks, however solely these editions assist boot to VHD.

A VHD that holds an working system and may boot to that working system is known as a native-boot VHD. That is additionally know as boot to VHD. File system partitions that the native boot VHD incorporates are robotically seen.


We have now separate articles through which we describe how one can work with VHDs:

Bear in mind

A Digital Exhausting Disk a single file that’s structured to signify a normal laborious disk drive. VHD makes use of out there disk area on the pc. VHD information have a .vhd file extension. VHD could be mounted or dynamically increasing. VHDs could be hooked up to present working system. We will use Disk Administration, DiskPart, WIM2VHD and BCDEdit to handle VHD information. VHD that holds an working system and may boot to that working system is known as a local boot VHD or boot to VHD.