What is Virtual Hard Disk

  

Rollins Duke   
Published: May 13th, 2024 • 4 Min Read

VHD or the Virtual hard disk created with Microsoft Hyper-V, Virtual PC, Virtualbox is basically a disk image sort of file format that is used to store the complete data of a hard disk. Hyper-V in the Microsoft Windows Server 2012 has also introduced a new VHD format version called the “VHDX” that is specifically designed for handling the current as well as increasing data storage support in the future.

Prime Advantages of the New VHDX File Format

VHDX format in MS Windows Server very nicely addresses most of the technical demands of any evolving organization by 1) augmenting the storage capacity, 2) salvaging the data against corruption, and 3) improving performance over big-sector disks.

VHDX File format – Technical Overview

• Supports virtual hard drive capacity for data storage as large as 64 TB.
• Protects well against data loss and data corruption in the event of power failure as it logs updates to the metadata structures of VHDX.
• Improves virtual hard drive format alignment so as to work nicely over big sector disks.

VHDX Format Features

• Bigger sizes of the blocks for differencing & dynamic disks, helping them for attuning to the workload requirements.
• The 4-KB logical sector virtual drive is allowing for better and augmented performance while using it by the applications and for the workloads, which are designed for the 4-KB sectors.
• It stores the custom metadata for the file which the end-user may wishes to record, like, the OS version or the applied patches.
• Better efficiency in the representation of the data (which is also called as “trim”). This results in lesser file size and also helps the principal physical storage device to retrieve the unused space.

VHD vs. VHDX

• Storage Capacity:
  A great advantage of the VHDX format is its much bigger virtual storage capacity than the previous VHD format. Before the release of the MS Windows Server 2012, the Hyper-V virtual hard drive only had 2 TB storage limit; whereas, the VHDX files can store up to 64 TB of data.
• Performance:
  The advantage of the VHDX format is not just limited to the augmented data storage capacity, but also, the VHDX files are designed to easily work under today’s conditions with the modern day hardware along with having a 4 KB logical sector size which helps in improving the performance as compared to the older VHD files.
• Data Corruption:
  The new VHDX files provide ample protection safeguarding the data against corruptions in case of power failures. This is done by constantly keeping a track of the metadata updates, which is a feature that was not there in the VHD format.

The Hyper-V VHD or the New VHDX?

Let us look at some of the advantages, disadvantages, and limitations