Virtual hard disk
(also VHD)
Virtual hard disk definition
A virtual hard disk is a file format that simulates a physical hard disk drive. VHD serves as a container for operating systems, applications, and data.
Used predominantly in virtual machines, VHDs allow these systems to operate on various host environments and facilitate easy storage management through capabilities like backup and transfer. They also support dynamic expansion and contraction of disk storage.
See also: Virtual drive, Virtual tape library
A brief history of virtual hard disk
The virtual hard disk emerged in the late 1990s, initially developed by Connectix and later integrated into Microsoft’s virtualization products. Designed to simulate physical hard drives, VHDs became essential for operating virtual machines.
In 2005 Microsoft opened the VHD format to other vendors, further solidifying its industry standard status. Today, VHDs are crucial in cloud computing and data centers.
Use cases of virtual hard disk
- System testing and development. Developers use virtual hard disks to create and test multiple configurations of operating systems and applications in a controlled environment.
- Disaster recovery and backup. Organizations employ VHDs for efficient backup and disaster recovery processes. They enable quick restoration of system states.
- Server consolidation and virtualization. Virtual hard disks facilitate server consolidation. They allow multiple virtual servers to run on a single physical server.