Glossary¶
Overview¶
This glossary provides definitions for key terms and concepts used throughout the RH OVE ecosystem documentation.
A¶
Admission Control : A Kubernetes mechanism that validates and mutates API requests before they are persisted to etcd. In RH OVE, this includes OpenShift built-in controllers, KubeVirt webhooks, and Kyverno policies.
Ansible : An open-source, agentless IT automation tool used for configuration management, application deployment, orchestration, and task automation across multiple systems.
Argo CD : A declarative GitOps continuous delivery tool for Kubernetes that automatically synchronizes applications with their desired state defined in Git repositories.
B¶
Backup Policy : A set of rules and schedules that define how, when, and what data should be backed up in the RH OVE environment, typically managed by Rubrik.
C¶
CDI (Containerized Data Importer) : A Kubernetes extension that provides facilities for enabling Persistent Volume Claims (PVCs) to be used as disks for KubeVirt VMs by importing, uploading, and cloning disk images.
Cilium : An open-source software for providing and transparently securing network connectivity and load balancing between application workloads using eBPF technology.
CMDB (Configuration Management Database) : A repository that acts as a data warehouse for IT installations, containing information about configuration items and their relationships, often integrated with ServiceNow.
CNI (Container Network Interface) : A specification and libraries for writing plugins to configure network interfaces in Linux containers, with Cilium being the recommended CNI for RH OVE.
CRD (Custom Resource Definition) : A Kubernetes extension mechanism that allows users to define custom resources that extend the Kubernetes API, extensively used in KubeVirt for VM management.
CSI (Container Storage Interface) : A standard for exposing arbitrary block and file storage systems to containerized workloads on Kubernetes, enabling storage vendors to develop plugins that work across different container orchestration systems.
D¶
DataVolume : A KubeVirt CRD that provides a declarative way to import, upload, and clone data into PVCs, serving as the primary storage mechanism for VM disks.
Day-2 Operations : Post-deployment operational activities including maintenance, monitoring, updates, scaling, and optimization of the RH OVE environment.
Dynatrace : An application performance monitoring and observability platform that provides full-stack monitoring for RH OVE environments.
E¶
eBPF (extended Berkeley Packet Filter) : A kernel technology that allows programs to run in kernel space without changing kernel source code or loading kernel modules, used by Cilium for high-performance networking.
etcd : A distributed, reliable key-value store used by Kubernetes to store all cluster data, providing a consistent and highly-available data store for cluster state.
G¶
GitOps : An operational framework that takes DevOps best practices used for application development and applies them to infrastructure automation, using Git as the single source of truth.
Grafana : An open-source platform for monitoring and observability that enables visualization, alerting, and exploration of metrics from multiple data sources including Prometheus, Elasticsearch, and others.
H¶
Hugepages : Large memory pages that can improve performance for memory-intensive applications by reducing memory management overhead in virtual machines.
Hubble : The network observability layer for Cilium that provides deep visibility into network flows, security policies, and performance metrics.
Helm : A Kubernetes package manager that helps you manage Kubernetes applications through charts, which are packages of pre-configured Kubernetes resources.
HyperConverged : A top-level CRD in OpenShift Virtualization that manages the deployment and configuration of all virtualization components.
I¶
Ingress : A Kubernetes API object that manages external access to services in a cluster, typically HTTP, providing load balancing, SSL termination, and name-based virtual hosting.
Istio : An open-source service mesh that provides a uniform way to secure, connect, and monitor microservices, offering traffic management, security, and observability features.
K¶
KubeVirt : An open-source Kubernetes add-on that enables running virtual machines alongside containers in a Kubernetes cluster, forming the foundation of OpenShift Virtualization.
Karmada : A Kubernetes management system that enables multi-cluster application management and provides centralized control plane for managing workloads across multiple Kubernetes clusters.
Kyverno : A policy engine designed for Kubernetes that validates, mutates, and generates configurations using admission controller webhooks and background scans.
M¶
MacVLAN : A Linux networking driver that allows creating multiple virtual network interfaces with different MAC addresses on a single physical network interface, commonly used with Multus for VM networking.
Multus CNI : A Container Network Interface (CNI) plugin that enables attachment of multiple network interfaces to pods and VMs in Kubernetes, allowing complex networking scenarios beyond single-network configurations.
N¶
NAD (Network Attachment Definition) : See NetworkAttachmentDefinition.
NetworkAttachmentDefinition : A CRD used by Multus that defines additional network interfaces for pods and VMs, enabling multi-network configurations beyond the default cluster network.
Network Plumbing Working Group : A Kubernetes community working group focused on developing networking enhancements, including Multus CNI and related multi-networking technologies.
NUMA (Non-Uniform Memory Access) : A computer memory design used in multiprocessing where memory access time depends on the memory location relative to the processor, important for VM performance tuning.
O¶
OLM (Operator Lifecycle Manager) : A component of the Operator Framework that helps users install, update, and manage the lifecycle of Kubernetes operators and their associated services.
OpenShift Virtualization : Red Hat's enterprise virtualization solution that allows running virtual machines alongside containers on the same OpenShift platform.
P¶
Prometheus : An open-source systems monitoring and alerting toolkit with a dimensional data model, flexible query language (PromQL), efficient time series database, and modern alerting approach.
PVC (Persistent Volume Claim) : A request for storage by a user or application in Kubernetes, used extensively in RH OVE for VM disk storage.
Q¶
QEMU Guest Agent : A daemon that runs inside virtual machines to provide enhanced integration between the VM and the hypervisor, enabling better monitoring and management.
R¶
RBAC (Role-Based Access Control) : A method of restricting system access to authorized users based on their roles within an organization, fundamental to multi-tenant security in RH OVE.
RH OVE (Red Hat OpenShift Virtualization Engine) : Red Hat's solution for running virtual machines on OpenShift, based on the upstream KubeVirt project.
Rubrik : An enterprise data management platform that provides backup, recovery, and data protection services, certified for integration with RH OVE.
S¶
ServiceNow : An IT service management platform that provides CMDB functionality and can be integrated with RH OVE for automated configuration tracking.
SR-IOV (Single Root I/O Virtualization) : A specification that allows efficient sharing of PCIe devices between virtual machines, enabling high-performance networking for VMs.
T¶
Tekton : A Kubernetes-native open-source framework for creating continuous integration and delivery (CI/CD) systems, allowing developers to build, test, and deploy applications.
Terraform : An open-source infrastructure as code tool that allows users to define and provision data center infrastructure using a declarative configuration language.
V¶
VirtualMachine (VM) : A KubeVirt CRD that represents a virtual machine definition, including CPU, memory, storage, and network configurations.
VirtualMachineInstance (VMI) : A KubeVirt CRD that represents a running virtual machine instance, showing the actual runtime state of a VM.
VirtualMachineInstanceReplicaSet : A KubeVirt CRD that ensures a specified number of VMI replicas are running, similar to Kubernetes ReplicaSets for pods.
virtctl : A command-line tool for managing KubeVirt virtual machines, providing functionality to start, stop, console access, and manage VMs.
VLAN (Virtual Local Area Network) : A network configuration that enables the logical partitioning of a physical network into multiple broadcast domains, improving security and network management.
VPC (Virtual Private Cloud) : A logically isolated section of a cloud provider's infrastructure where users can launch resources in a virtual network that they define.
W¶
WebAssembly (WASM) : A binary instruction format for a stack-based virtual machine that enables high-performance applications on web browsers and server environments, increasingly used for cloud-native applications.
Common Acronyms¶
- ADR: Architecture Decision Record
- API: Application Programming Interface
- CDI: Containerized Data Importer
- CI/CD: Continuous Integration/Continuous Deployment
- CMDB: Configuration Management Database
- CNI: Container Network Interface
- CPU: Central Processing Unit
- CRD: Custom Resource Definition
- CSI: Container Storage Interface
- DNS: Domain Name System
- HA: High Availability
- IAM: Identity and Access Management
- I/O: Input/Output
- IOPS: Input/Output Operations Per Second
- ITSM: IT Service Management
- JSON: JavaScript Object Notation
- LDAP: Lightweight Directory Access Protocol
- NFS: Network File System
- OAuth: Open Authorization
- OIDC: OpenID Connect
- OLM: Operator Lifecycle Manager
- RBAC: Role-Based Access Control
- REST: Representational State Transfer
- SAML: Security Assertion Markup Language
- SIEM: Security Information and Event Management
- SLA: Service Level Agreement
- SSD: Solid State Drive
- TLS: Transport Layer Security
- VLAN: Virtual Local Area Network
- VM: Virtual Machine
- VMI: Virtual Machine Instance
- VPC: Virtual Private Cloud
- WAF: Web Application Firewall
- WASM: WebAssembly
- YAML: YAML Ain't Markup Language
This glossary provides essential terminology for understanding and working with the RH OVE ecosystem. Terms are regularly updated as the technology and documentation evolve.