Private Cloud
Private Clouds are cloud environments solely dedicated to the end user, usually within the user’s firewall. Although private clouds traditionally ran on-premise, organizations are now building private clouds on rented, vendor-owned data centers located off-premise. All clouds become private clouds when the underlying IT infrastructure is dedicated to a single customer with completely isolated access.[1]
How Private Cloud Works and the Private Cloud Architecture[2]
How Private Cloud Works Private cloud is a single-tenant environment, meaning all resources are accessible to one customer only—this is referred to as isolated access. Private clouds are typically hosted on-premises in the customer's data center. But, private clouds can also be hosted on an independent cloud provider’s infrastructure or built on rented infrastructure housed in an offsite data center. Management models also vary—the customer can manage everything itself or outsource partial or full management to a service provider.
Private Cloud Architecture Single-tenant design aside, private cloud is based on the same technologies as other clouds—technologies that enable the customer to provision and configure virtual servers and computing resources on demand in order to quickly and easily (or even automatically) scale in response to spikes in usage and traffic, to implement redundancy for high availability, and to optimize utilization of resources overall. These technologies include the following:
- Virtualization, which enables IT resources to be abstracted from their underlying physical hardware and pooled into unbounded resource pools of computing, storage, memory, and networking capacity that can then portioned among multiple virtual machines (VMs), containers, or other virtualized IT infrastructure elements. By removing the constraints of physical hardware, virtualization enables maximum utilization of hardware, allows hardware to be shared efficiently across multiple users and applications, and makes possible the scalability, agility, and elasticity of the cloud.
- Management software gives administrators centralized control over the infrastructure and applications running on it. This makes it possible to optimize security, availability, and resource utilization in the private cloud environment.
- Automation speeds tasks—such as server provisioning and integrations—that would otherwise need to be performed manually and repeatedly. Automation reduces the need for human intervention, making self-service resource delivery possible.
In addition, private cloud users can adopt cloud native application architectures and practices—such as DevOps, containers, and microservices—that can bring even greater efficiency and flexibility and enable a smooth transition to a public cloud or hybrid cloud environment in the future.
Virtual Private Cloud[3]
A virtual private cloud (VPC) is an on-demand configurable pool of shared resources allocated within a public cloud environment, providing a certain level of isolation between the different organizations (denoted as users hereafter) using the resources. The isolation between one VPC user and all other users of the same cloud (other VPC users as well as other public cloud users) is achieved normally through allocation of a private IP subnet and a virtual communication construct (such as a VLAN or a set of encrypted communication channels) per user. In a VPC, the previously described mechanism, providing isolation within the cloud, is accompanied with a VPN function (again, allocated per VPC user) that secures, by means of authentication and encryption, the remote access of the organization to its VPC resources. With the introduction of the described isolation levels, an organization using this service is in effect working on a 'virtually private' cloud (that is, as if the cloud infrastructure is not shared with other users), and hence the name VPC.
VPC is most commonly used in the context of cloud infrastructure as a service. In this context, the infrastructure provider, providing the underlying public cloud infrastructure, and the provider realizing the VPC service over this infrastructure, may be different vendors. is an on-demand configurable pool of shared resources allocated within a public cloud environment, providing a certain level of isolation between the different organizations (denoted as users hereafter) using the resources. The isolation between one VPC user and all other users of the same cloud (other VPC users as well as other public cloud users) is achieved normally through allocation of a private IP subnet and a virtual communication construct (such as a VLAN or a set of encrypted communication channels) per user. In a VPC, the previously described mechanism, providing isolation within the cloud, is accompanied with a VPN function (again, allocated per VPC user) that secures, by means of authentication and encryption, the remote access of the organization to its VPC resources. With the introduction of the described isolation levels, an organization using this service is in effect working on a 'virtually private' cloud (that is, as if the cloud infrastructure is not shared with other users), and hence the name VPC.
VPC is most commonly used in the context of cloud infrastructure as a service. In this context, the infrastructure provider, providing the underlying public cloud infrastructure, and the provider realizing the VPC service over this infrastructure, may be different vendors.
source: Wikipedia
Advantages and Disadvantages of Private Cloud[4]
Advantages of a private cloud
The main advantage of a private cloud is that users don't share resources. Because of its proprietary nature, a private cloud computing model is best for businesses with dynamic or unpredictable computing needs that require direct control over their environments, typically to meet security, business governance or regulatory compliance requirements.
When an organization properly architects and implements a private cloud, it can provide most of the same benefits found in public clouds, such as user self-service and scalability, as well as the ability to provision and configure virtual machines (VMs) and change or optimize computing resources on demand. An organization can also implement chargeback tools to track computing usage and ensure business units pay only for the resources or services they use.
In addition to those core benefits inherent to both cloud deployment models, private clouds also offer:
- Increased security of an isolated network.
- Increased performance due to resources being solely dedicated to one organization.
- Increased capability for customization.
Disadvantages of a private cloud
Private clouds also have some disadvantages. First, private cloud technologies, such as increased automation and user self-service, can bring some complexity to an enterprise. These technologies typically require an IT team to rearchitect some of its data center infrastructure, as well as adopt additional management tools. As a result, an organization might have to adjust or even increase its IT staff to successfully implement a private cloud. They can also be expensive; often, when a business owns its private cloud, it bears all the acquisition, deployment, support and maintenance costs involved.
Hosted private clouds, while not outright owned by the user, can also be costly. The service provider takes care of basic network maintenance and configuration in a hosted deployment, which means the user needs to subscribe and pay regularly for that offered service. This can end up being more expensive than the upfront cost of complete ownership in the long run, and sacrifices some of the control over maintenance that complete ownership guarantees. Although users will still be operating in a single-tenant environment, providers are likely serving multiple clients, and promising each of them a catered, custom environment. If an incident occurs on the provider's end -- an improperly maintained or overburdened server for example -- users may find themselves facing the same problems the public cloud presents: unreliability and lack of control.