Private Cloud Reference Model

1 Introduction

This document gives an overview of a Private Cloud Reference Model. For the purposes of this document, a Reference Model is defined as the problem definition, requirements, and scope for a specific domain including the identification of all layers (or subdomains) and any interactions or dependencies between the components. 

This Reference Model forms the basis, or cornerstone, for all Reference Architecture in a Private Cloud. It not only defines the domain and drives coherency of approach amongst the many authors who contribute to the Private Cloud Reference Architecture documentation set. Every contributor and reviewer of the Reference Architecture documentation should use the Reference Model to understand the broad landscape of the problem domain before being able to decide if the existing guidance meets their needs or identify what new guidance may be required.

The Reference Model will initially be depicted as a single diagram and the remainder of the document will decompose each layer and describe its components.

This is a general purpose document that provides foundational context and approach for the development of Reference Architecture documentation. Therefore, the first audience for this document are all those people who are involved in the development of any Private Cloud Reference Architecture. All reviewers of the Reference Architecture materials can use this document to determine “fit for purpose” for their materials. The applicability of this guidance is much broader than the development activity as any architect, service manager, or technical decision maker will benefit from an understanding of the problem domain and the approach to producing the Reference Architecture.

2 Reference Model

The Private Cloud Reference Model defines the scope and the problem space for its domain. The model acts as the “guide-rails” to assist architects’ efforts to holistically address the development of a private cloud architecture. Additionally, it provides a common vocabulary and shared understanding across all constituencies.

The Reference Model below depicts a number of layers, which are further decomposed into specific problem spaces or components.


Figure 1: The Private Cloud Reference Model

The Reference Model is split into the following layers:

• The Software, Platform, and Infrastructure Layers represent the technology stack, where each provides services to the layer above.
• The Service Operations and Management Layers represent the process perspective and includes the management tooling required to implement aspects of the process.
• The Service Delivery Layer represents the alignment between business and Information Technology (IT).

It is a deliberate attempt to blend technology and process (for example, Information Technology Infrastructure Library perspectives because Cloud Computing is as much about the Service Management as it is about the technologies involved in it.

At first it may not seem much different from traditional IT; but remember, this is not a Reference Architecture, it is a Reference Model and is defined as the Many of IT’s problems continue to be the same, from both a technology and operational perspective; however, the differences now include some enabling technologies and radical approaches based on the experience and concepts associated with Cloud Computing. From an operational perspective, the desire to adopt good IT Service Management practices has also been around for a long time. But many organizations have not been effective in implementing these best practices and this hinders their success. Cloud Computing is driving a new emphasis on operational rigor, casting a fresh light on best-practices and forcing IT to re-think some of its fundamental concepts.

The layers are further defined as follows:

• Service Delivery Layer: Represents those Service Management activities that require input and interaction with the business and service owner. The components are not only responsible for that interaction, but also the translation of business requirement into technology and operational capabilities. This layer represents the business perspective on the basis of IT.
• Software Layer: Provides the applications and software that support a business activity (for example, CRM). The Software Layer consumes Virtual Machines (VM) services from the Infrastructure Layer and may consume application services from the Platform Layer.
• Platform Layer: Provides a set of platform-level (above operating system level) building blocks which can be consumed by the Software Layer. It consumes hypervisor services from the Infrastructure Layer and is managed by the Management Layer.
• Infrastructure Layer: Provides resilient hypervisor services to the Platform Layer and is managed by the Management Layer. The Infrastructure, Platform, and Software Layers represent the enabling technology perspective within IT.
• Service Operations Layer: Represents Service Management and operational processes carried out by IT operations and support staff.
• Management Layer: Provides management services to the Infrastructure, Platform, and Software Layers. It is comprised of the suite of management tools necessary to support IT Service and Operations Layer and implements the operational processes. The Management Layer provides a baseline set of capabilities to the Infrastructure Layer and an incremental set to the Platform Layer and the Software Layer. The Operations and Management Layers represent the operational perspective within IT.

2.1 Service Delivery Layer

The Service Delivery layer is the interface between business and IT. It serves as the conduit for translating business requirements into IT services and is responsible for managing ongoing delivery of those services. These capabilities are common to all services: Infrastructure as a Service (IaaS), Platform as a Service (PaaS), and Software as a Service (SaaS).


Figure 2: Service Delivery Layer Components

As the primary interface with the business, the Service Delivery Layer is expected to know or obtain answers the following questions:

• What services does the business want?
• What level of service are business decision-makers willing to pay for?
• How can private cloud move IT from being a cost center to becoming a strategic partner to the business?

With these questions in mind, there are two main problems within the Service Layer that IT must address:

• How do we provide a cloud-like platform for business services that meets business objectives?
• How do we adopt an easily understood, usage-based cost model that can be used to influence business decisions?

An organization must adopt the following private cloud principles in order to meet the business objectives of a cloud-like service:

• Perception of Infinite Capacity: From an end user’s perspective, cloud services appear to have no capacity constraints; and there is no limit to the volume of service users can consume.
• Perception of Continuous Availability: An end user should never observe any interruption in cloud services, even if failures occur within the cloud environment.
• Resiliency over Redundancy Mindset: Provider focus is on maintaining service availability through resiliency instead of redundancy.
• Service Provider's Approach in Delivering Infrastructure: IT organizations should adopt a service provider model based on infrastructure service definitions with clear capabilities from provider and consumer perspectives.
• Drive Predictability: Remove as much variation from the environment as possible to increase predictability.
• Minimize Human Involvement: A highly automated environment is required to achieve resiliency.
• Optimization of Resource Usage: From the provider’s perspective, resources should be optimized to maximize utilization and minimize waste, driving efficiency and reducing cost.
• Encourage Desired Consumer Behavior: Use cost, quality, and agility to influence consumer behavior in ways congruent with principles.

The components of the Service Delivery Layer are:

• Financial Management: Financial Management incorporates the functions and processes used to meet a service provider’s budgeting, accounting, metering, and charging requirements. The primary concerns around Financial Management in a private cloud are providing cost transparency to the business and structuring a usage-based cost model for the consumer. Achieving these goals is a basic precursor to achieving the principle of encouraging desired consumer behavior.
• Demand Management: Demand Management involves understanding and influencing customer demands for services, plus the provision of capacity to meet these demands. The principles of perceived infinite capacity and continuous availability are fundamental to stimulating customer demand for cloud-based services. A resilient, predictable environment and predictable capacity management are necessary to adhere to these principles. Cost, quality, and agility factors influence consumer demand for these services.
• Business Relationship Management: Business Relationship Management is the strategic interface between the business and IT. If an IT department is to adhere to the principle that it must act as a service provider, mature Business Relationship Management is critical. The business should define the functionality of required services and partner with IT on solution procurement. The business will also need to work closely with IT to define future capacity requirements to continue adhering to the principle of perceived infinite capacity.
• Service Catalog: The output of Demand and Business Relationship Management will be a list of services or service classes offered and documented in the service catalog. This catalog describes each service class, eligibility requirements for each service class, service-level attributes, targets included with each service class (such as availability targets), and cost models for each service class. The catalog must be managed over time to reflect changing business needs and objectives.
• Service Life Cycle Management: Service Life Cycle Management takes an end-to-end management view of a service. A typical journey starts with identification of a business need, through Business Relationship Management, to the time when that service becomes available. Service strategy drives service design. After launch, the service is transitioned to operations and refined through continual service improvement. Taking a service provider’s approach is key to successful Service Life Cycle Management.
• Service-Level Management: Service-Level Management is the process of negotiating Service-Level Agreements (SLAs) and making sure the agreements are met. SLAs define target levels for cost, quality, and agility by service class as well as the metrics for measuring actual performance. Managing SLAs is necessary for achieving the perception of infinite capacity and continuous availability. This, too, requires a service provider’s approach by IT.
• Continuity and Availability Management: Availability Management defines processes necessary to achieve the perception of continuous availability. Continuity Management defines how risk will be managed in a disaster scenario to make sure minimum service-levels are maintained. The principles of resiliency and automation are fundamental here.
• Capacity Management: Capacity Management defines the processes necessary to achieve the perception of infinite capacity. Capacity must be managed to meet existing and future peak demand while controlling under-utilization. Business Relationship and Demand Management are key inputs into effective Capacity Management and require a service provider’s approach. Predictability and optimization of resource usage are primary principles in achieving Capacity Management objectives.
• Information Security Management: Information Security Management strives to make sure that all requirements are met for confidentiality, integrity, and availability of the organization’s assets, information, data, and services. An organization’s particular information security policies will drive the architecture, design, and operations of a private cloud. Resource segmentation and multi-tenancy requirements are important factors to consider during this process.

2.2 Software Layer

The Software Layer provides the business applications with solution-specific runtime components necessary to deliver a business service. It will consume hypervisor services from the Infrastructure Layer and may consume application services from the Platform Layer. The Software Layer provides interfaces to end-users.

2.3 Platform Layer

The Platform Layer provides application services to the Software Layer and consumes hypervisor services from the Infrastructure Layer. Platform Layer interfaces will vary; some examples of Platform Layer interface include Hypertext Transfer Protocol (HTTP) and Representational State Transfer (REST).

2.4 Infrastructure Layer

The Infrastructure Layer provides hypervisor services (VM resources) to the Platform and Software Layers. It defines the capabilities necessary for these VMs to execute; it includes hypervisor, physical servers, network devices, storage systems, and facilities (which include space, power, cooling, and physical interconnects).


Figure 3: Infrastructure Layer Components

Infrastructure Layer components include:

• Network: Network services provide addressing and packet delivery for the provider’s physical infrastructure and the consumer’s VMs. Network capability includes physical and virtual network switches, routers, firewalls, and Virtual Local Area Network (VLAN).
• Compute: Compute services supply the physical resources such as CPU, Random Access Memory (RAM), NIC, Video, and Storage used by the provider to deliver VMs to consumers. It contains the physical server hardware and parent OS.
• Storage: Storage provides physical storage devices to the provider, which exposes these services to consumers as virtual disks. Storage should be connected to a network for VM portability.
• Hypervisor: The hypervisor provides VM services by partitioning and presenting compute, network, and storage services.
• Facilities: Facilities represent the physical building, racks, power, cooling, and physical interconnects.

2.5 Service Operations Layer

The Service Operations Layer defines the operational processes and procedures necessary to deliver IT as a Service. This layer uses IT Service Management concepts that can be found in prevailing best practice such as ITIL or Microsoft Operations Framework (MOF).

The main focus of the Service Operations Layer is to execute the business requirements defined at the Service Delivery layer. Cloud-like service attributes cannot be achieved through technology alone; mature IT service management is also required.

The Service Operations capabilities are common to all three services; IaaS, PaaS, and SaaS.


Figure 4: Service Operations Layer Components

The components of the Service Operations Layer include:

• Change Management: Change Management is responsible for controlling the life cycle of all changes. Its primary objective is to implement beneficial changes with minimum disruption to the perception of continuous availability. Change Management determines the cost and risk of making changes and balances them against the benefits to the business or service. Driving predictability and minimizing human involvement are the core principles behind a mature Change Management process.
• Service Asset and Configuration Management: Service Asset and Configuration Management maintains information on the assets, components, and infrastructure needed to provide a service. Accurate configuration data for each component, and its relationship to other components, must be captured and maintained. This data should include historical and expected future states in addition to the current state, and be easily available to those who need it. Mature Service Asset and Configuration Management processes are necessary for achieving predictability.
• Release and Deployment Management: Release and Deployment Management is responsible for seeing that changes to a service are built, tested, and deployed with minimal disruption to the service or production environment. Change Management provides the approval mechanism (determining what will be changed and why), but Release and Deployment Management is the mechanism for determining how changes are implemented. Driving predictability and minimizing human involvement in the release and deployment process are key to achieving cost, quality, and agility goals.
• Knowledge Management: Knowledge Management is responsible for gathering, analyzing, storing, and sharing information within an organization. Mature Knowledge Management processes are necessary to achieve a service provider’s approach and a key element of IT service management.
• Incident and Problem Management: The goal of Incident and Problem Management is to resolve disruptive, or potentially disruptive, events with maximum speed and minimum disruption. Problem Management also identifies root causes of past incidents and seeks to identify and prevent (or minimize the impact of) future ones. In a private cloud, the resiliency of the infrastructure helps make sure that faults, when they occur, have minimal impact on service availability. Resilient design promotes rapid restoration of service continuity. Driving predictability and minimizing human involvement are necessary to achieve this resiliency.
• Request Fulfillment: The goal of Request Fulfillment is to manage user requests for services. As IT adopts a service provider’s approach, it should define available services in a service catalog based on business functionality. The catalog should encourage desired user behavior by exposing cost, quality, and agility factors to the user. Self-service portals, when appropriate, can assist the drive towards minimal human involvement.
• Access Management: The goal of Access Management is to deny access to unauthorized users while making sure that authorized users have access to needed services. Access Management implements security policies defined by Information Security Management at the Service Delivery Layer. Maintaining smooth access for authorized users is critical to achieving the perception of continuous availability. Adopting a service provider’s approach to Access Management will also make sure that resource segmentation and multi-tenancy are addressed.
• Systems Administration: The goal of System Administration is to perform the daily, weekly, monthly, and as-needed tasks required for system health. A mature approach to Systems Administration is required for achieving a service provider’s approach and for driving predictability. The vast majority of Systems Administration tasks should be automated.

2.6 Management Layer

The Management Layer defines the capabilities required to execute and implement the Operation and Service Layer processes and procedures to support IaaS, PaaS, and SaaS. These capabilities are incremental moving up through the Infrastructure, Platform and Software Layers.


Figure 5: Management Layer Components Related to Infrastructure

The components of the Management Layer related to the Infrastructure Layer are:

• Service Reporting: Service Reporting is the mechanism for producing and delivering performance reports on Service Levels. The system requirements for the service reporting toolset should be driven by the service-level requirements defined by Service-Level Management in the IT Service Layer.
• Service Management System: A Service Management System is a set of tools designed to facilitate Service Management processes. Ideally, these tools should be able to integrate data and information from the entire set of tools found in the Management Layer. It should also be capable of processing and present the data as needed. At a minimum, the Service Management System should be linked to the Configuration Management System (CMS), commonly known as the Configuration Management Database (CMDB), and should log and track incidents, problems, and changes. It is also preferred that the Service Management System be integrated with the Service Health Modeling system so that incident tickets can be auto-generated.
• Service Health Monitoring: The Service Health Monitoring system makes sure that services meet all service-level targets. This system should be aware of each component required to provide a service – and its relationship and dependencies on other components. The Service Health Monitoring system should identify when a service is approaching a performance threshold or component failure and either resolve the issue itself or alert Operations.
• Configuration Management System: A Configuration Management System (CMS) is the definitive hub for collecting, storing, managing, updating, and presenting data about all Configuration Items (CIs) and their relationships. A CMS is composed of a number of Configuration Management Databases (CMDBs), each of which manages a subset of configuration data. A CMS should ideally integrate and correlate the information from the CMDBs for processing, analysis, and presentation. The CMS should also have configuration monitoring capability to identify, report, and repair when configurations fall out of the desired state.
• Fabric Management: Fabric Management is the toolset responsible for managing workloads of virtual hosts, virtual networks, and storage. Fabric Management provides the orchestration necessary to manage the life cycle of a consumer’s workload (one or more VMs that collectively deliver a service; Microsoft Office SharePoint Portal being one example).
• Deployment and Provisioning Management: Deployment and Provisioning Management is the toolset used to carry out the processes defined by Release and Deployment Management in the Operations Layer. Deployment results in creation or installation of a computer unit or service component in generic, unequipped fashion; provisioning is the process of applying service-specific and instance-specific attributes to the deployed resource.
• Data Protection: Data Protection provides the capability to backup and restore data, hosts, and infrastructure and service components. Data protection policies should be defined in the IT Service Layer by Service-Level Management and Information Security Management.
• Network Management: Network Management manages the underlying network fabric, including VLANs, switch ports, load balancers, and firewall rules. Network Management also includes a set of network services that support IaaS; for example, Dynamic Host Configuration Protocol (DHCP), Domain Name System (DNS), and Pre-Boot Execution Environment (PXE).
• Security Management: Security Management defines and reports on the security policies (for example, password complexity levels) that apply to the infrastructure. It provides security services such as a directory, authentication, and authorization.

Private Cloud Providers

Private cloud software has to work with the virtualization layer that is providing the resources, enabling a management interface for the self-service aspect along with a management interface for the IT administrator. All of this has to be accomplished at a reasonable price and with adequate support if you plan on making your private cloud a part of your core business strategy. With all software investments today, and especially when it comes to virtualization and cloud software, the additional question of going with open source also has to be taken into consideration with the pros and cons that come with it. Thus below, you'll notice a mix of proprietary as well as open source private cloud options and what each has to offer. to know more about private cloud vendor keep on reading the article

Microsoft Private Cloud

While Microsoft was a bit late to the virtualization and cloud arena, the software giant has spent considerable resources catching up and leveraging experience to avoid some of the mistakes other vendors in this space have made. Microsoft's private cloud software is part of the System Center 2012 R2 offering. System Center incorporates several products under one umbrella including Virtual Machine Manager, Data Protection Manager, Endpoint protection and Operations Manager.

• Microsoft's System Center will support and centrally manage Windows 2012 Hyper-V hosts along with third party hypervisors from Citrix and VMware; KVM is a notable exception that is not included at this time. While the hypervisors are agnostic, the current lack of active third party network providers, including Cisco, is worth noting and may be limiting to some customers.
• Microsoft's private cloud offering focuses on the application life cycle combined with automation and monitoring in one package. This, coupled with a straightforward ability to create self-service portals based on mature IIS features, helps with the installation process. Leveraging the .NET framework does allow for additional extensions and troubleshooting.
• Security can be leveraged off of existing Active Directory resources without the complexity of setting up single sign on (SSO). However this can open up additional security risks based on existing Windows Server vulnerabilities.
• While the pieces in the package may not go feature for feature when compared to other offerings, the single SKU does make licensing and purchasing easier.

VMware vCloud Suite Private Cloud

VMware is one of the oldest players in the virtualization market and has an established record of performance and reliability. VMware's products have the ability to scale to some of the most demanding workloads. VMware has incorporated several products into its private cloud offering allowing customers to choose ala cart what features they would like to use. VMware's vCloud Suite comes in three different versions (Standard, Advanced and Enterprise) with each incorporating additional products and features.

• VMware vCloud Suite does support other hypervisors, including Hyper-V and KVM, however extensive single pane of glass management is not advertised, as the favored hypervisor is ESXi.
• The Advanced edition of vCloud Suites adds vRealize Business for vSphere and Enterprise version includes vCenter Site Recovery Manager on top of the vRealize Business Suite. vRealize Business offers cost, usage and metering ability while vCenter Site Recovery Manager is policy-based disaster recovery.
• The vCloud Suite is packaged and requires license upgrades together as a single entity, however it is a collection of separate products, which can lead to confusion with support, and installation when compared to other offerings. 
• Frequent product name changes lead to confusion on what the products do, which ones are needed, upgradable or even owned in some cases.
• vCloud has the ability to integrate with VMware's software defined networking offering NSX, however this is an additional licensing fee with all versions of vCloud.
• Established enterprise class security at the hypervisor and network layers for easy user integration with Active Directory single sign on and its complexities are required.
• Support for VMware Virtual SAN and OpenStack allow for flexibility in both storage and third party cloud integration tools. 

OpenStack Private Cloud

OpenStack is one of the most popular open source cloud operating options today. It has the ability to manage compute, storage and networking and deploy them is an easy to use, but somewhat feature limited dashboard. Unlike VMware and Microsoft, OpenStack does not have its own hypervisor. 

• OpenStack can be used with VMware's ESXi, Microsoft's Hyper-V, or Citrix Xen, however it is most often used with KVM, which is also open source. With more vendors including OpenStack APIs this will encourage more adoption.
• OpenStack supports a wide range of software and hardware due to its open source nature. This allows for flexible architecture that can support both legacy and new hardware platforms.
• While the capital cost of the software is free (since it's open source) the soft cost in training your IT staff will have to be accounted for. 
• Similar to other open source offerings, a community support model is in place over paid maintenance, this may require trained staff for immediate support needs.
• With so many community developers and quality feedback from users the complexity of installation and operation is simpler than might be expected. OpenStack is directly focused on the cloud platform and does not have additional pieces which reduces complexity.

Platform9 OpenStack Private Cloud

Platform9 is a private cloud provider based on OpenStack that does not reside onsite. Platform9 uses an OpenStack as a service model to allow organizations to manage their private clouds from an external cloud. While this might seem a bit unusual for a private cloud solution, the key point to remember is that your data still resides inside your data center, it's simply the management piece that is external to your company.

• Platform9 currently supports the KVM hypervisor with VMware ESXi in beta testing. Currently there are no plans for Hyper-V or Citrix Xen listed.
• Being a hosted solution there is no software to install or upgrade. Platform9 handles all patches and upgrades to the OpenStack core.
• Simplified user portal, image management and infrastructure discovery allow for reduced administrative overhead while leveraging the scalability and reliability of OpenStack.
• Policy based deployments with infrastructure monitoring brings many of the popular public cloud features into the private cloud space without limited complexity.
• No capital costs to get started; the solution is priced as a monthly service fee.

Apache CloudStack Private Cloud

Another contender in the open source private cloud space is Apache's CloudStack. The CloudStack solution supports a wide range of hypervisors from VMware, Microsoft, Citrix and KVM. CloudStack is offered as a complete solution minus the hypervisor, allowing companies to have a robust management interface, usage metering and image deployment. Storage tiering and Active Directory are also included with limited software defined networking.

• Unlike OpenStack, which focuses on the core cloud aspect, CloudStack is looking to provide everything under the single open source umbrella.
• CloudStack is an economical approach to the private cloud with many popular features included. One concern is the quality of those features, along with the support that exists with open source software.
• It includes a Java-based management agent, which may cause some concerns regarding performance, security and version splintering.

Private Cloud Feature Comparison

Microsoft Private Cloud
Compatibility	Single pane of glass for Hyper-V, VMware ESXi and Citrix Xen servers, although detail of management support is not clear.
Complexity	Single product makes it easy (but expensive) to purchase. Because System Center contains so many related products, installation and upgrades can be complex.
Security	Relies on the existing Active Directory / IIS frameworks allowing for ease of operations.
Summary	Microsoft's private cloud with System Center is a good option businesses looking to get started with a private cloud. Cost is packaged, but System Center itself is a very complex product and a bit large in overhead when compared to some of the other offerings.
VMware vCloud Suite Private Cloud
Compatibility	Ability to manage top three hypervisors, but limited information on to what detail.
Complexity	Suite variants with add-ons can make purchasing complex. Products are separate features making installing and upgrades more complex.
Security	Mature security in core products, integration with Active Directory requires single sign on.
Summary	VMware's vCloud Suite is a collection of best of breed technologies that allow for enterprise class performance, reliability and scalability. The ala cart approach combined with frequent name changes does increase the complexity for licensing, purchasing, installing and maintaining, even as the majority of products are bundled in a loose collection.
OpenStack Private Cloud
Compatibility	Primary focus is on KVM but VMware's hypervisor is gaining support. Limited attention on Citrix Xen and Microsoft Hyper-V.
Complexity	Fairly easy to get started with community created documentation.
Security	Security is based on security domains and trusts. Third-party LDAP server can do authentication; support for multi-factor authentication is available as well.
Summary	OpenStack is a private cloud offering that can scale from SMBs to larger enterprises. While there is concern over support with open source software, a robust community does exist. With the open source nature of OpenStack, several vendors have used it as their cloud layer, adding additional features and functions.
Platform9 OpenStack Private Cloud
Compatibility	Official support for KVM; VMware hypervisor support is in beta. No published plans for Citrix Xen or Microsoft Hyper-V at this time.
Complexity	Quick and easy to get started with as there is no software to install.
Security	Management is being done offsite, which could present security concerns for some organizations.
Summary	Platform9 is the cloud platform for the folks that want many of the features of a cloud without the management complexity. While you won't find some of the advanced features that other vendors include, such as software defined networking, Platform9 will appeal to those looking to get started without the lead-time and costs of many of the other solutions. The biggest hurtle with Platform9 today is the lack of full VMware and Hyper-V support.
Apache CloudStack Private Cloud
Compatibility	Supports VMware ESXi, Citrix Xen, Microsoft Hyper-V and KVM. No single pane of glass for detailed management.
Complexity	Multiple products under a single open source umbrella may present challenges for installation and configuration, coupled with primary support being forum based is cause for concerns.
Security	While support for Active Directory exists, along with security zones, the inclusion of Java-based management agents may present additional security concerns.
Summary	CloudStack is a complete open source private cloud offering that can scale up to enterprise needs. However, with limited customer references, until CloudStack receives more exposure in the enterprise space it may be more suited for smaller or classroom deployments.

Virtual Machine Migration

Cloud computing is the delivers the computing services over the internet. Cloud services help individuals and organization to use data that are managed by third parties or another person at remote locations. Virtual Machine (VM) is an emulation of a particular computer system. In cloud computing, Virtual machine migration is a useful tool for migrating Operating System instances across multiple physical machines. It is used to load balancing, fault management, low-level system maintenance and reduce energy consumption. There are various techniques and parameters available for VM migration.

for detail read the research paper by title"Virtual Machine Migration in Cloud Computing" published in "International Journal of Grid Distribution Computing"

Choosing the Best Conference Call Provider

Most companies that use audio conferencing facilities prefer to hold the services of trustworthy conference call providers. In general, the host of the conference call has to pay for each minute of the call; this may appear quite pricey in the end. Still, there is also an alternative option that can be very useful for those businesses that can’t afford paying such expenses. This alternative is a free conference call provider. There are no fees charged to the consumers for the conference call, so there is no bill to pay. Below you will read some information on how free conference call providers work, and when the service appears as a practical option.

The first thing to take into account is that free conference call providers are not absolutely free. The fees won’t be seen on the statement released by the free conference call provider, but it will appear as a payment for per minute created on each participant’s personal telephone fees. Than you might have a question why is it called free, if it is not actually? The meaning of free conferencing is based on the actuality that the conference call provider is not charging setup fees, or matter fees for use of their lines.

The fact that free conference call providers are offering this type of service can be explained for several reasons. And one reason between this is that free conference calling necessitates not much in the system of apparatus and staff. This stands for a very low operating rate that can be simply solved by regular usage of their services.

Over the years, call conferencing has evolved from being a business apparatus that was within the domain of the big companies, to a common way to hold meetings for companies of any size. Conference calls are basically telephone calls in which the party which calls adds any number of other parties who are present at other locations. For making this possible, companies use conference call providers to maintain the telephonic connection between them.

Call conference has become an indispensable tool in business. This has cut down the company’s cost. For example, a company has many branches. Interacting with each and every branch is difficult. For this, call conferencing is the best solution. Call conferencing is now used for personal use also. Nowadays, the competition between various conference call providers has become fierce. But, there are many companies which provide low quality call conferencing. Therefore, for a disturbance free conference call, it has become essential to choose the right service provider. Before choosing any conference call providers, one must have the knowledge about the facilities it provides as well as he/she must go through different reviews of the providers. It is better to make test calls to check if the sound quality is clear. It is always advised to check the budget also. There are many features which are provided by the call providers. They provide the facility to record the conference. Privacy and security is ensured. Digital connections are also available which are clear. One can have access to it at any time, be it day or night. A toll free number is also available to help customers clear any query. The desktop sharing facility is also available. Some service providers also offer web-cast, which is like a conference call, videotaped and streamed on the internet. Nowadays, call conferencing has become affordable. The price, though vary with the features. There are basically three types of call conferencing. These are audio conferencing, video conferencing and web conferencing. In audio conferencing, only a telephone is required. It is quite popular due to its low cost. In video conferencing, a web-cam and a television are required. But it comes with few technical problems. The web conferencing is a recently developed technology. It uses the internet to hold conferences.

Happy new year and great christmas

good wishes for the ocassion

Thinking of a startup!

 answer the following question...

1. What Problem you are going to solve?

2. how other have solve this problem? how differently you will solve it?

3. List down the benefits of this solution to the public.

.......

wait for next post

Cloud Security and Hadoop

This topic can be covered with the working of Hadoop on multi node cluster having some of node on cloud, i will try to cover once i am with some good information. If any of you are with please share