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A to Z Full Forms and Acronyms

What is Virtual Data Plane and Policy-Driven Control Plane?

In This Article, we'll discuss What is Virtual Data Plane and Policy-Driven Control Plane?

Virtual Data Plane

The word “plane” has a number of uses in the English language, but it is used in virtualization to refer to a specific level or layer in an organization’s IT architecture.

The virtual data plane stores data for later retrieval, and applies data services such as compression (reducing the size of files), replication (continuous copying of data), caching (storing temporarily for quick access), snapshots (images of a system at a particular point in time), deduplication (eliminating duplicate copies) and availability (the proportion of time that a system is working properly).

While data services are provided by a physical array or implemented in software, the virtual data plane abstracts the services and presents them to the policy-driven control plane (which we will speak about in the next section) for use. The virtual data plane also applies whatever policy has been selected to the objects in the virtual datastore.

In today's model, the data plane operates on rigid infrastructure-centric entities such as LUNs or storage volumes. In the VMware SDS model, the data plane is virtualized by abstracting the physical hardware resources and aggregating them into logical pools of capacity. These logical pools of capacity are known as virtual datastores, and they can be flexibly used and managed.

By making a virtual disk the fundamental unit of management for all storage operations in the virtual datastores, exact combinations of resources, and data services can be configured and independently-controlled for each virtual machine.

The virtual data plane in the VMware model is delivered through vSAN for X86 (i.e., industry-standard, “off-the-shelf”) hyper-converged storage, and through vSphere virtual volumes for external storage SAN and NAS.

Policy-Driven Control Plane

In the VMware software-defined storage model, there is a bridge between the infrastructure and applications called the control plane, which helps dictate standardized management and automation between different tiers of storage. A virtual machine is the primary unit of management that is thought of as a convenient container for an application or application component. Policies are associated with application containers (VMs) and carried out by the control plane.

Through SDS, storage classes of service (which are types of storage classes designed for different use cases) become logical entities that can be completely controlled by software and carried out through policies. Policy-driven automation simplifies provisioning on a large scale, enables dynamic control over individual service levels for each virtual machine, and ensures that all legal requirements (referred to as “compliance”) are met throughout the life-cycle of the application (from its beginnings as a concept to its last use).

Aspects of the policy-driven control plane (“perspectives”) are visible to specific roles in a typical IT environment: application administrator, storage administrator, data protection administrator, business operations, and so on. This wider access wouldn’t be possible in a typical storage environment, where each type of storage array has its own separate management tools that can’t create multiple perspectives for different team members.

The policy-driven control plane can be programmed through public application programming interfaces (also known as “API”. APIs will be discussed in section 5.4). The APIs are used to control policies through scripting and cloud automation tools which in turn enable self-service consumption of storage for application “tenants”. (Where a software application is used by a group of people, each of those people is called a “tenant”.) VMware’s storage policy-based management (SPBM) enables the policy-driven control plane. SPBM makes possible management over external storage such as SAN and NAS through vSphere virtual volumes and over X86 storage through vSAN. We will be looking at SPBM in more detail shortly.

We spoke briefly about “converged” infrastructure (where traditionally individual technology disciplines merge) in section 4, and we’ll be looking at “hyper-converged infrastructure” (HCI) in section 5. For now, it would be helpful for you to know that HCI brings innovation to the management layer, allowing application requirements (not hardware resources) to be the priority in storage decisions.

A to Z Full Forms and Acronyms

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