Private cloud is a well-defined term that government standards groups and the commercial cloud industry have pretty much agreed upon, and while some think its use is waning, recent analysis indicates that spending on private cloud is still growing at a breakneck pace
Private cloud is a well-defined term that government standards groups and the commercial cloud industry have pretty much agreed upon, and while some think its use is waning, recent analysis indicates that spending on private cloud is still growing at a breakneck pace.
What is a private cloud ?
There are four types of cloud – public, community, hybrid, and private cloud, according to the National Institute for Standards and Technology.
NIST says that private cloud has some unique characteristics that set it apart from the rest: “The cloud infrastructure is provisioned for exclusive use by a single organization comprising multiple consumers (e.g., business units). It may be owned, managed, and operated by the organization, a third party, or some combination of them, and it may exist on or off premises ”.
That’s what sets private cloud apart, but it also shares five characteristics with the other types of cloud, NIST says.
The first, on-demand self-service, means that end users can provision compute resources themselves without asking help from IT.
The second, broad access. requires that the resources in the cloud are accessible via most every type of device from workstations and laptops to tablets and phones.
The third, resource pooling, which makes for more overall efficient use of the compute resources, means various tenants share resources that are dynamically assigned over and over. In a private cloud this means that different divisions of an organization share resources, but they are exclusively available for just that organization. They are not shared with third parties as is the case with multi-tenancy services.
The fourth, rapid elasticity, enables ramping capacity up or down as needed and releasing resources for use by others when the need passes.
Finally, measured service insures that providers and users can measure how much of various resources – storage, processing, bandwidth, numbers of user accounts – are used so they can be allocated in a way that optimizes use of the resources.
Virtualization is just a part of private cloud
Just utilizing virtualization by throwing a hypervisor on a server does not comprise private cloud computing. While virtualization is a key component of cloud computing, it is not a cloud by itself.
Virtualization technology allows organizations to pool and allocate resources, which are both part of NIST's definition. But other qualities around self-service and the ability to scale those resources is needed for it to technically be considered a cloud environment.
A private cloud – compared to public or hybrid clouds – refers specifically to resources used by a single organization, or when an organization's cloud-based resources are completely isolated.
Private cloud economics
One of the biggest misconceptions about private cloud is that the cloud will save money. It can and often does, but it doesn’t inherently do so.
The up-front costs can be considerable. For example, automation technology, an important part of a private-cloud network, can be a significant investment for many IT organizations. The result can be the ability to reallocate resources more efficiently, and it may allow some organizations to reduce their overall capital expenditures for new hardware, which can also save money. But overall savings are not assured.
Gartner analysts say the primary driving benefit of adopting a private cloud model should not be cost savings, but rather increased agility and dynamic scalability, which can improve time-to-market for businesses that make use the technology.