A public cloud is offered as a service, usually over an Internet connection. On the other hand, private clouds are deployed inside the firewall and managed by the user organization.
Private Cloud is a new approach in Cloud Computing with benifits,
- Easily accessible and reliable utility service.
- Along with qualities such as self-service, pay-as-you-go charges, on-demand provisioning and scalability.
- Private clouds eliminate the ‘rewrite everything’ effect of public cloud computing.
- They offer the trusted control that users seek while ensuring that IT meets the security, control, service levels and compliance requirements of the business.
Virtualization decouples the physical IT infrastructure from the hosted applications and services, thus allowing greater efficiency and flexibility into processes. The virtualization of servers, storage and networks enables the mobility of applications and data—not just across servers and storage arrays in the same data center, but also across data centers and networks. Consolidation is a critical application of virtualization, enabling IT departments to regain control of distributed resources by creating shared pools of standardized resources which can be rationalized and centrally managed.
A few applications like email archiving, document management systems and data backup can be migrated on to the Private Cloud. As these models stabilize and organizations scale up, more business-critical applications can be moved on to the cloud. This helps organizations to deliver internal IT services more effectively in a cost-effective manner.
Remember below before implementing Private Cloud computing.
Private Cloud architecture implementation
The fabric of virtualization has its limits. For example, there is little flexibility in scaling a virtual machine. The scaling will be always limited to the maximum resources available on a particular physical server. For instance on a 24 core server with 32 GB RAM, you cannot have a virtual machine which has more than (or even equal to) 24 cores and 32 GB of RAM.
However, if there are 50 such servers, then you technically have 1200 Cores and 1.6 TB of RAM. But if an organization needs a machine with higher specs from its virtual infrastructure, say 50 cores and 64 GB of RAM, it's just not possible. The organization has to buy a new server with more than 50 cores and 50 GB of RAM. This can be used as a physical box or to create a virtual machine.
Selection of cloud middleware: It's best to opt for a Private Cloud Architecture Supported By your existing server virtualization platform. A XEN user can select between Ubuntu Enterprise Cloud or Enomaly. If you are a VMware fan, then sticking with VMware based private cloud architecture is a better option. Microsoft Hyper-V users will have to wait for the time being. Microsoft has promised to launch its Dynamic Datacenter Toolkit, which will let users build Private Cloud architecture based on Hyper-V.