Disaster Recovery Glossary

This glossary defines key disaster recovery and Windows deployment terms. Several terms originated in Windows 2000-era recovery and installation technology, but the definitions below have been modernized to clarify their role in current Windows Server, endpoint deployment, imaging, and recovery planning.

A

Answer File

An answer file is a structured configuration file used to automate operating system installation or deployment. In legacy Windows 2000 environments, it supplied answers to setup prompts during installation. In modern Windows deployment, the equivalent concept appears in unattended installation files, provisioning packages, Windows Deployment Services workflows, Microsoft Deployment Toolkit configurations, and cloud-managed deployment processes.

Authoritative Restore

An authoritative restore is an Active Directory recovery operation in which restored directory objects are marked as the authoritative version so that they replicate outward to other domain controllers. It is used when deleted or corrupted Active Directory objects must be recovered and then treated as the correct copy across the domain or forest.

Automated System Recovery

Automated System Recovery, or ASR, was a legacy Windows recovery mechanism used to restore critical system configuration after serious operating system failure. In modern Windows Server environments, ASR has largely been replaced by Windows Server Backup, System State backup, Bare Metal Recovery, recovery media, virtualization snapshots, and cloud-based recovery options.

B

Backup Set

A backup set is a collection of files, volumes, system components, or application data captured together during a backup operation. In disaster recovery planning, backup sets must be protected, cataloged, tested, and retained according to recovery requirements.

Bare Metal Recovery

Bare Metal Recovery, or BMR, is the process of restoring a failed server to working condition without requiring the original operating system installation to be present. A BMR backup includes the operating system files and critical volumes needed to recover a server that cannot boot or has lost its original system disk.

Boot Image

A boot image is an image file used to start a computer into a preinstallation, recovery, or deployment environment. In Windows deployment, boot images are often based on Windows PE and may be distributed through Windows Deployment Services, Configuration Manager, recovery media, or other deployment systems.

Business Continuity

Business continuity is the broader discipline of keeping essential business functions operating during or after a disruption. Disaster recovery is one component of business continuity, focused specifically on restoring systems, data, services, and infrastructure after failure.

C

CD-Based Image

A CD-based image is a legacy installation image created from the contents of a Windows installation CD-ROM. In modern environments, this concept is usually replaced by ISO images, Windows Imaging Format files, recovery images, deployment shares, or cloud-managed installation media. The purpose remains the same: to provide a known installation source that can be used to rebuild or recover a system.

Checkpoint

A checkpoint is a saved state of a virtual machine or system configuration that can be used to return to an earlier condition. In disaster recovery planning, checkpoints are useful for short-term rollback, but they are not a substitute for tested backups because they may depend on the health of the underlying host, storage, or virtualization platform.

Cloud Witness

A cloud witness is a type of failover cluster quorum witness that uses cloud storage, such as an Azure storage account, to provide an additional quorum vote. It helps a Windows Server failover cluster maintain availability and avoid split-brain behavior when cluster nodes are distributed across locations.

Cluster Quorum

Cluster quorum is the voting mechanism used by a failover cluster to determine whether enough cluster members are online to safely continue operating. If quorum is lost, the cluster stops clustered roles to reduce the risk of data corruption or split-brain operation.

Computer Disaster

A computer disaster is an event that causes or threatens the loss of data, system availability, network connectivity, application functionality, or business continuity. Examples include disk failure, malware infection, accidental deletion, failed updates, corrupted operating system files, hardware loss, data-center outage, cloud service disruption, or ransomware attack.

Critical Volume

A critical volume is a disk volume required for the operating system or server role to start and function correctly. In Windows Server backup planning, critical volumes are important because Bare Metal Recovery depends on restoring the volumes needed to boot and recover the server.

D

Disaster Protection

Disaster protection refers to the preventive controls, recovery procedures, backup systems, monitoring practices, and continuity plans used to reduce the risk of data loss or downtime. Modern disaster protection may include regular backups, immutable storage, endpoint protection, recovery testing, high availability, replication, failover planning, identity protection, and documented recovery runbooks.

Disaster Recovery

Disaster recovery is the process of restoring technology services, data, servers, applications, and network access after a disruptive event. In Windows Server environments, disaster recovery may involve System State backup, Bare Metal Recovery, Active Directory recovery, failover clustering, virtual machine restoration, storage replication, and documented recovery procedures.

Disaster Recovery Plan

A disaster recovery plan is a documented set of procedures for restoring systems after a major failure. A good plan identifies protected systems, backup locations, recovery contacts, restoration order, recovery time objectives, recovery point objectives, validation steps, and escalation procedures.

Domain Controller Recovery

Domain controller recovery is the process of restoring a failed Active Directory domain controller or rebuilding it safely within the domain. Depending on the failure, recovery may involve System State restore, non-authoritative restore, authoritative restore, metadata cleanup, FSMO role management, or promoting a replacement domain controller.

F

Failover

Failover is the process of moving a workload, service, application, or clustered role from a failed system to another available system. In disaster recovery, failover reduces downtime by allowing services to continue running on alternate infrastructure.

Failover Cluster

A failover cluster is a group of independent servers, called nodes, that work together to increase the availability of applications and services. If one node fails, clustered roles can move to another node, helping maintain service availability during hardware, software, or maintenance events.

File Share Witness

A file share witness is a type of cluster quorum witness that uses a shared folder as an additional vote in the cluster quorum process. It is commonly used when a cluster needs a lightweight witness and shared disk storage is not appropriate.

Full Server Backup

A full server backup captures the volumes and system components needed to restore an entire server. It is broader than a file-only backup and is often used when the recovery goal is to rebuild the server rather than recover only selected files.

G

Globally Unique Identifier (GUID)

A globally unique identifier, or GUID, is a 128-bit value used to uniquely identify an object, component, device, policy, application, or configuration item. In Windows environments, GUIDs are commonly used in Active Directory, Group Policy, registry entries, COM components, disk identifiers, and deployment metadata.

Golden Image

A golden image is a standardized operating system image that contains the approved configuration, applications, updates, and settings for deployment. In disaster recovery and endpoint management, golden images help rebuild systems consistently after failure or replacement.

Group Policy Object (GPO)

A Group Policy Object is a collection of policy settings used to configure users, computers, security rules, desktop behavior, software restrictions, scripts, and system preferences in an Active Directory environment. In modern Windows Server environments, GPOs remain important for domain-joined systems, although many organizations also use cloud-based management through Microsoft Intune, Microsoft Entra ID, and mobile device management policies.

H

High Availability

High availability is the design goal of keeping systems operational with minimal interruption. It usually relies on redundancy, clustering, load balancing, replicated storage, monitoring, and automatic failover. High availability reduces downtime, while disaster recovery focuses on restoring service after a larger failure.

Hyper-V Replica

Hyper-V Replica is a Windows Server feature that replicates virtual machines from one Hyper-V host or cluster to another. It can be used as part of a disaster recovery strategy when virtual machines must be recovered at a secondary location after a host, storage, or site failure.

I

Image Backup

An image backup captures a disk, volume, or system state in a form that can be restored as a complete unit. Image backups are useful when the recovery requirement is to rebuild a system quickly rather than reinstall the operating system and applications manually.

Immutable Backup

An immutable backup is a backup copy that cannot be modified or deleted during its retention period. Immutable backups are especially important for ransomware resilience because they help ensure that attackers cannot encrypt, alter, or erase all recovery points.

Install Image

An install image is an operating system image used to install Windows on a target computer. In Windows Deployment Services and related deployment tools, install images are commonly stored as Windows Imaging Format files and are paired with boot images used to start the deployment process.

ISO Image

An ISO image is a disk image file that contains the contents of optical media or installation media. In disaster recovery, ISO images may be used for operating system installation, recovery environments, diagnostic tools, or virtual machine boot media.

M

Microsoft Deployment Toolkit (MDT)

Microsoft Deployment Toolkit is a Microsoft deployment framework used to automate Windows operating system and application deployment. In disaster recovery and endpoint rebuild scenarios, MDT can help standardize installation tasks, driver injection, application installation, and post-deployment configuration.

N

Non-Authoritative Restore

A non-authoritative restore is an Active Directory recovery operation in which a domain controller is restored from backup and then updated by replication from other domain controllers. It is commonly used when the domain controller itself must be recovered but the rest of the directory contains the current valid data.

P

Preboot Execution Environment (PXE)

Preboot Execution Environment, or PXE, is a network boot technology that allows a computer to start from a network-based boot program before an operating system is installed. In Windows deployment, PXE is commonly associated with Windows Deployment Services, imaging, recovery media, and large-scale operating system deployment.

Protection Group

A protection group is a collection of servers, workloads, or data sources that are backed up according to a common policy. Protection groups are commonly used in enterprise backup systems to define what is protected, how often backups occur, and how long recovery points are retained.

Q

Quorum Witness

A quorum witness is an additional voting component used by a failover cluster to help maintain quorum. A witness may be configured as a cloud witness, disk witness, or file share witness. Its purpose is to help the cluster determine which side should continue operating when failures or network partitions occur.

R

Recovery Media

Recovery media is bootable media used to start a failed computer into a repair, restore, diagnostic, or deployment environment. Examples include USB recovery drives, ISO images, Windows PE media, Windows installation media, and network-delivered boot images.

Recovery Point

A recovery point is a specific backup version or captured state from which data or systems can be restored. Recovery points are used to select how far back a system, file, application, or server should be recovered.

Recovery Point Objective (RPO)

Recovery Point Objective, or RPO, defines the maximum acceptable amount of data loss measured in time. For example, an RPO of one hour means the organization expects to lose no more than one hour of data if recovery is required.

Recovery Time Objective (RTO)

Recovery Time Objective, or RTO, defines the maximum acceptable amount of time required to restore a system, application, or service after a disruption. RTO helps determine whether an organization needs simple backups, standby systems, clustering, replication, or automated failover.

Remote Installation Preparation (RIPrep)

Remote Installation Preparation, or RIPrep, was a legacy Windows deployment tool used with Remote Installation Services to create an image of a configured reference computer. Administrators used it to clone a standard desktop configuration, including operating system settings, desktop customizations, and locally installed applications. In modern environments, this role is typically handled by Windows Imaging Format files, Sysprep, Windows Deployment Services, Microsoft Deployment Toolkit, Configuration Manager, or cloud-based provisioning.

Remote Installation Services (RIS)

Remote Installation Services was a legacy Microsoft technology used to deploy Windows operating system images to client computers over the network, often by using PXE boot. RIS was associated with Windows 2000 and early Windows Server deployment models. It was later replaced by Windows Deployment Services, and many organizations now supplement or replace traditional imaging with Microsoft Deployment Toolkit, Configuration Manager, Autopilot, Intune, or cloud-based device provisioning.

Replication

Replication is the process of copying data, configuration, virtual machines, directory information, or application state from one location to another. In disaster recovery, replication can reduce recovery time and data loss, but it should be combined with backups because replication may also copy corruption or accidental deletion.

Restore Point

A restore point is a saved system state that can be used to roll back selected operating system or configuration changes. Restore points are useful for limited rollback scenarios, but they are not a replacement for full backups, System State backup, or Bare Metal Recovery.

Runbook

A runbook is a documented set of operational steps used to perform a recovery or administrative procedure. A disaster recovery runbook may include server dependencies, restore order, commands, screenshots, validation checks, escalation contacts, and post-recovery testing procedures.

S

Source Computer

A source computer is the reference machine or installation source used to create, store, or provide deployment files. In legacy RIS terminology, the source computer contained the Windows installation files. In modern disaster recovery and deployment planning, the equivalent may be a reference image, deployment share, golden image, recovery server, virtual machine template, or cloud-hosted provisioning source.

Split-Brain

Split-brain is a cluster failure condition in which separated parts of a cluster each believe they should continue operating independently. This can create conflicting writes, inconsistent data, or corruption. Windows Server failover clustering uses quorum voting and witness configuration to reduce the risk of split-brain operation.

System State Backup

A System State backup captures critical operating system and server role components needed to recover Windows Server configuration. On a domain controller, System State includes Active Directory database components, SYSVOL, boot files, registry data, and related system information required for directory recovery.

Sysprep

Sysprep is the Microsoft System Preparation tool used to generalize a Windows installation before imaging or deployment. It removes machine-specific information so the image can be safely deployed to other computers without duplicating identifiers or configuration artifacts.

V

Volume Shadow Copy Service (VSS)

Volume Shadow Copy Service, or VSS, is a Windows service that coordinates consistent point-in-time snapshots of volumes. Backup tools use VSS to capture files, system data, and application-aware backups while the system is running.

W

wbadmin

wbadmin is a Windows command-line backup and recovery utility. It can be used to start backups, perform System State backups, recover data, and support administrative recovery operations from an elevated command prompt.

Windows Deployment Services (WDS)

Windows Deployment Services is a Microsoft server role used to deploy Windows operating systems over the network. WDS commonly uses PXE boot, boot images, install images, and Windows Imaging Format files to support centralized deployment and recovery workflows.

Windows Imaging Format (WIM)

Windows Imaging Format, or WIM, is a file-based disk image format used by Microsoft deployment tools. WIM files can store boot images, install images, and customized Windows images used for operating system deployment, recovery media, and enterprise imaging.

Windows Recovery Environment (WinRE)

Windows Recovery Environment, or WinRE, is a recovery environment used to troubleshoot startup problems, repair Windows installations, access recovery tools, and support system restoration. It is often used with recovery media, system images, and advanced startup options.

Windows Server Backup

Windows Server Backup is the built-in Windows Server feature used to create and restore backups of files, volumes, applications, System State, and Bare Metal Recovery data. It is suitable for many small and medium recovery scenarios, although larger enterprises often supplement it with dedicated backup platforms.