Home > Storage > PowerStore > Virtualization and Cloud > Dell PowerStore: VMware vSphere with Tanzu and TKG Clusters > Terminology
The following table provides definitions for some of the terms that are used in this document.
Term | Definition |
Appliance | Solution containing a base enclosure and attached expansion enclosures. The size of an appliance could be only the base enclosure or the base enclosure plus expansion enclosures. |
Cloud Native Storage (CNS) | A vCenter Server component that manages persistent volumes. |
Container | Software that packages code and dependencies making it portable to run across computing environments. |
Container Image Virtual Disk | A local cache of images that can be used in pods instead of pulling down images from an external container registry |
Ephemeral Virtual Disk | Transient storage for vSphere Pods. Each vSphere Pod has one ephemeral disk that exists throughout the life cycle of the vSphere Pod. Ephemeral disks persist across container restarts but are removed when the vSphere Pod is removed. |
Fibre Channel (FC) protocol | Protocol used to perform IP and SCSI commands over a Fibre Channel network. |
File system | Storage resource that can be accessed through file-sharing protocols such as SMB or NFS. |
First Class Disk (FCD) | Also known as an Improved Virtual Disk (IVD). A type of virtual disk used to back persistent volumes. It is unique in that it is designed to offer operational and life cycle management without being associated with a virtual machine. |
Internal snapshot (replication snapshot) | Unified snapshots created by the system that are part of an asynchronous replication session. These snapshots are only visible in the PowerStore CLI or PowerStore REST API, and manual modification is not possible. Each asynchronous replication session uses up to two internal snapshots that are taken on the source and destination storage resources. Each session also takes up one read/write snapshot on the destination storage system. The last successful internal read-only (RO) snapshots for source and destination storage resources and are used as a common base. |
iSCSI | Provides a mechanism for accessing block-level data storage over network connections. |
kubectl | The official Kubernetes client. A command-line tool for interacting with the Kubernetes API. |
Network-attached storage (NAS) server | File-level storage server used to host file systems. A NAS server is required to create file systems that use SMB or NFS shares. |
Network File System (NFS) | An access protocol that allows data access from Linux or UNIX hosts on a network. |
Persistent Volume | Storage resource that is used to maintain stateful data for containerized applications. A static persistent volume is a virtual disk (.vmdk) created in advance by the vSphere administrator. A dynamic persistent volume is provisioned on demand using a storage class. Both types are consumed by a Persistent Volume Claim (PVC). Persistent volumes maintain stateful data by having a life cycle independent of the containerized application that uses it. When the consuming pod is deleted, the persistent volume remains. |
Persistent Volume Claim | A request for static or dynamic persistent storage. A persistent volume claim (PVC) is tied to a persistent volume. |
PowerStore base enclosure | Enclosure containing both nodes (node A and node B) and 25 NVMe drive slots |
PowerStore cluster | Multiple appliances in a single grouping. Clusters can consist of one appliance or more. Up to four PowerStore appliances can be clustered by adding appliances as required. |
PowerStore Command Line Interface (PSTCLI) | Tool which can be installed on an operating system to manage a PowerStore system. It allows a user to perform tasks on the storage system by typing commands instead of using the user interface. |
PowerStore expansion enclosure | Enclosures that can be attached to a base enclosure to provide additional storage. |
PowerStore Manager | An HTML5 management interface for creating storage resources and configuring and scheduling protection of stored data on PowerStore. PowerStore Manager can be used for all management of PowerStore native replication. |
PowerStore node | Storage controller that provides the processing resources for performing storage operations and servicing I/O between storage and hosts. Each PowerStore appliance contains two nodes. |
PowerStore Representational State Transfer (REST) API | Set of resources (objects), operations, and attributes that provide interactive, scripted, and programmatic management control of the PowerStore cluster. |
PowerStore Q model | Container-based storage system that is running on purpose-built hardware. This storage system supports unified (block and file) workloads, or block-optimized workloads. The PowerStore Q model supports Quad-Level Cell (QLC) NVMe SSDs for data storage. |
PowerStore T model | Container-based storage system that is running on purpose-built hardware. This storage system supports unified (block and file) workloads, or block-optimized workloads. The PowerStore T model supports Triple-Level Cell (TLC) NVMe SSDs for data storage. |
Snapshot | Also called a unified snapshot, a snapshot is a point-in-time view of a storage resource or data stored on a storage resource. A user can recover files from a snapshot, restore a storage resource from a snapshot, or provide snapshot data access to a host. When a snapshot is taken, it creates an exact copy of the source storage resource and shares all blocks of data with it. As data changes on the source, new blocks are allocated and written to. Unified snapshot technology can be used to take a snapshot of a block or file storage resource. |
Storage class | A type of storage available to and used to back a persistent volume. A storage class abstracts underlying storage constructs. A storage class is used to describe storage requirements for a persistent volume. Used by DevOps teams in persistent volume claims. |
Storage resource | Top-level object that a user can provision which is associated with a specific quantity of storage. All host access and data-protection activities are performed at this level. In this document, storage resources refer to resources that support replication such as volumes, volume groups, and thin clones. |
Tanzu Kubernetes Cluster | Deployed on a vSphere with Tanzu Supervisor Cluster by using the Tanzu Kubernetes Grid Service, it is a full distribution of the open-source Kubernetes container orchestration platform. Tanzu Kubernetes clusters use the open-source Photon operating system from VMware and are built, signed, and supported by VMware. |
Thin clone | Read/write copy of a thin block storage resource (volume, volume group, or VMware vSphere VMFS datastore) that shares blocks with the parent resource. |
User snapshot | A snapshot that is created manually by the user or by a protection policy with an associated snapshot rule. This snapshot type is different than an internal snapshot, which the system takes automatically using asynchronous replication. |
Virtual Volumes (vVols) | VMware storage framework which allows VM data to be stored on individual Virtual Volumes. This ability allows data services to be applied at a VM-granularity level while using Storage Policy Based Management (SPBM). |
Volume | A block-level storage device that can be shared out using a protocol such as iSCSI or Fibre Channel. It represents a SCSI logical unit. |
Volume group | Storage instance which contains one or more volumes within a storage system. Volume groups can be configured with write-order consistency and help organize the storage that is allocated for particular hosts. |
vStorage API for Array Integration (VAAI) | VMware API that allows storage-related tasks to be offloaded to the storage system. |
vSphere API for Storage Awareness (VASA) | VMware API that provides additional insight about the storage capabilities in vSphere. |
vSphere Namespace | Organizational unit or abstraction onto which vSphere administrators apply policies and assign to development teams. Typically contains vSphere Pods or a Tanzu Kubernetes cluster. Backed by a Resource Pool to control resource limits. |
vSphere Pod | A virtual machine with a small footprint that runs one or more Linux containers. Right sized with explicit resource reservations for the workload that it accommodates at deployment. Equivalent to a Kubernetes pod. |
vSphere with Tanzu | vSphere infrastructure with workload management enabled making it a platform for running Kubernetes workloads natively on the hypervisor layer. |
Workload | In vSphere with Tanzu, workloads are applications deployed as standard virtual machines, containers running inside vSphere Pods, Tanzu Kubernetes clusters, or applications that run inside Tanzu Kubernetes clusters. |