Browse Definitions :
Definition

differencing disk

Contributor(s): Anil Desai

A differencing disk is a virtual hard disk (VHD) that stores changes made to another VHD or to the guest operating system. The purpose of differencing disks is to make it possible to maintain information about changes made so that they can be reversed if necessary.

Differencing disks are based on either a fixed-size or dynamically expanding VHD and can be configured with parent-child relationships to form a hierarchy of VHD types. The disks store all of the changes that would otherwise be written to the parent VHD.  However, it's important to remember that, as a rule, any VHD that serves as a parent must remain read-only.

Differencing disks can increase manageability, especially when multiple VMs share a similar configuration, and can dramatically reduce the amount of disk space required on a Virtual Server host computer. The drawbacks are that differencing disks can be difficult to manage and large hierarchies of disks can potentially lead to performance problems, especially if all of the physical VHD files are located on the same disks or arrays. Within Virtual Server, you can merge a differencing disk with its parent -- an operation that commits all the changes and either updates the base VHD or creates a new VHD file.

This was last updated in April 2013

Continue Reading About differencing disk

Start the conversation

Send me notifications when other members comment.

Please create a username to comment.

-ADS BY GOOGLE

File Extensions and File Formats

Powered by:

SearchCompliance

  • smart contract

    A smart contract, also known as a cryptocontract, is a computer program that directly controls the transfer of digital currencies...

  • risk map (risk heat map)

    A risk map, also known as a risk heat map, is a data visualization tool for communicating specific risks an organization faces. A...

  • internal audit (IA)

    An internal audit (IA) is an organizational initiative to monitor and analyze its own business operations in order to determine ...

SearchSecurity

SearchHealthIT

  • Health IT (health information technology)

    Health IT (health information technology) is the area of IT involving the design, development, creation, use and maintenance of ...

  • fee-for-service (FFS)

    Fee-for-service (FFS) is a payment model in which doctors, hospitals, and medical practices charge separately for each service ...

  • biomedical informatics

    Biomedical informatics is the branch of health informatics that uses data to help clinicians, researchers and scientists improve ...

SearchDisasterRecovery

  • risk mitigation

    Risk mitigation is a strategy to prepare for and lessen the effects of threats faced by a data center.

  • ransomware recovery

    Ransomware recovery is the process of resuming options following a cyberattack that demands payment in exchange for unlocking ...

  • natural disaster recovery

    Natural disaster recovery is the process of recovering data and resuming business operations following a natural disaster.

SearchStorage

  • RAID 5

    RAID 5 is a redundant array of independent disks configuration that uses disk striping with parity.

  • non-volatile storage (NVS)

    Non-volatile storage (NVS) is a broad collection of technologies and devices that do not require a continuous power supply to ...

  • petabyte

    A petabyte is a measure of memory or data storage capacity that is equal to 2 to the 50th power of bytes.

Close