Virtual Hard Disk

What Does Virtual Hard Disk Mean?

A virtual hard disk (VHD) is a type of disk drive that has similar functionalities as a typical hard drive but is accessed, managed and installed on a virtual machine infrastructure.


VHD is considered a file format and application, and is designed primarily to be used by virtual machines. It often contains the same hard drive sectors found on a physical hard drive, such as disk partitions and a file system.

Techopedia Explains Virtual Hard Disk

A virtual hard disk operates like a conventional physical hard disk, having all the capabilities to create disk sectors, files and folders, run an operating system and install and execute other applications. A virtual hard drive is created on a physical hard drive, but has a logical distribution of its own. In turn, it can host many different virtual hard drives simultaneously, depending on its size. Each of the created virtual hard disk is created as a tightly coupled drive and doesn’t overwrite or interfere with the operation of other VHDs.

Virtual hard disks can have a fixed or flexible disk size, which is managed and controlled by the virtualization manager or the parent operating system. Virtual hard disks were first conceived by Connectix Inc., which was purchased by Microsoft Co. to be used in their virtual PC as a virtual machine application for the Windows OS.


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Margaret Rouse
Technology Expert

Margaret is an award-winning technical writer and teacher known for her ability to explain complex technical subjects to a non-technical business audience. Over the past twenty years, her IT definitions have been published by Que in an encyclopedia of technology terms and cited in articles by the New York Times, Time Magazine, USA Today, ZDNet, PC Magazine, and Discovery Magazine. She joined Techopedia in 2011. Margaret's idea of a fun day is helping IT and business professionals learn to speak each other’s highly specialized languages.