VMware vSphere includes the VMware ESX / ESXi hypervisor, a type 1 hypervisor that functions as the virtualization server; the VMware vCenter Server, which manages vSphere environments; the VMware vSphere Client, which is used to install and manage virtual machines through the hypervisor; and VMware VMFS, the file system component from VMware.

Virtualization benefits

•In case of physical server the consolidation ratio would be 1:1, i.e., one OS mounted on a single server. But in case of virtualization, separate OS can be mounted on many VMs of a virtualized server. This server consolidation reduces energy cost by up to 80% resulting in “going green”.

•Server utilization is very high at 80% in case of virtualized one when compared to the physical server which is just 20-30% . This results in reducing hardware costs as applications no longer need their own server because each virtual machine on the physical server now runs them.

•Virtualization is flexible and powerful when compared to the bare metal installation in physical servers.

•The greatest benefit of server virtualization is the capability to move a virtual machine from one server to another quickly and safely. This is particularly useful during disaster recovery, most enterprise virtualization platforms contain software that helps automate the failover(recover VM) during a disaster.

•Having fewer physical servers means there are less of them to maintain and manage. This leaves your IT staff more time to spend on more productive tasks.

vCenter Server

VMware vCenter Server is a centralized management tool for multiple ESXi servers. The vCenter management server lets you bring those multiple ESXi servers together and make them into an HA cluster or use vMotion between them. VMware VCenter Server is designed primarily for VSphere, VMware’s platform for building virtualized cloud infrastructures.

VCenter Server is installed at the primary server of a virtualized data center and operates as the virtualization or virtual machine manager for that environment. It also provides data center administrators a central management console to manage all the system’s virtual machines.

ESX Server Cluster

A cluster is defined as “a group of tightly coupled computers that work together closely so that in many respects they can be viewed as though they are a single computer”. A VMware ESX Cluster is no difference.

With a VMware ESX cluster the below 2 benefits can be achieved-
•if one of the physical hosts goes down, the other physical host starts up the virtual guests machines that the original virtual host was running resulting in failover(VM HA – High Availability).
•if one physical host is over utilized by a virtual guest, that virtual guest is moved to the other physical host resulting in load balancing(VMware DRS – Distributed Resource Scheduler).

Virtual machine

A virtual machine (VM) is an operating system (OS) or application environment that is installed on software, i.e., hypervisor which imitates dedicated hardware. The end user has the same experience on a virtual machine as they would have on dedicated hardware.

Specialized software, called a hypervisor, emulates the PC client or server’s CPU, memory, hard disk, network and other hardware resources completely, enabling virtual machines to share the resources.

VMware vSphere Editions and Licensing

VMware vSphere Hypervisor
It is a free basic version with full hypervisor access.
It lacks some features amongst which its inability to be managed via vCenter Server and is limited to a maximum of 8 vCPUs per VM.

vSphere Essentials Kits
It is an all-in-one solution ideal for small offices. It enables consolidation and management of applications to reduce hardware and operating costs. It enables consolidation and management of applications to reduce hardware and operating costs—all with a low upfront investment. Regardless of choice, you can only have a maximum of 3 ESXi hosts and one instance of vCenter Server Essentials.

vSphere Essentials Plus Kits
This Kit adds features such as vSphere Vmotion, HA clustering, Vsphere data protection, replication, vshield endpoint to vSphere Essentials to enable always-on IT for the small environment. Essentials Plus is ideal for small businesses that, in addition to hardware and operation cost savings, are looking for maximization of application availability and business continuity with a low upfront investment. Here as well you can only have a maximum of 3 ESXi hosts and one instance of vCenter Server Essentials.

The main issue with Essentials is one of scalability which can only be addressed by upgrading to one of the Acceleration Kits.

vSphere Standard
This kit has all the Essentials Plus kit features plus storage vmotion, virtual volumes, storage policies, storage APIs etc., per CPU.Here there is no limit on the number of hosts.

vSphere Enterprise plus
This edition has additional features like the DRS clustering on top of the standard edition features which is the main reason companies go for this inspite of the huge cost.

The cost increases exponentially from the Essential kits to the Enterprise plus edition and are deployed based on the necessities of the companies purchasing them. The support for the kits varies from basic to production level and needs to be purchased separately.

Using the vSphere Client

The vSphere Client is the principal interface for administering vCenter Server and ESXi.
It is a web-based application that connects to the vCenter Server so IT administrators can manage installations and handle inventory objects in a vSphere deployment.

The vSphere Client acts as an administrative interface to access VMware hosts, which run VMware ESXi servers that run virtual machines (VMs). The vSphere Client attaches to the host servers. By using this interface, admins can create and manage VMs, as well as host resources and manage user permissions.

VMware introduced vSphere Client with the vSphere 5.1 release in 2012. At that time, the product was known as vSphere Web Client.Although vSphere Client was discontinued in vSphere version 6.0, it still has its place. Administrators can use vSphere Client to manage ESXi hosts in organizations that don’t have a vCenter Server.

Sources :
Workplace Learning & Experience

In contrast, IT cloud is about Cloudification of IT services ,i.e, cloud based service like Saas, Paas, Iaas. In IT cloud, the data centers are centralized. But in case of Telco deployments, network is split between radio and core elements. Going forward the split will change as the concept of distributed data centers will be introduced. One main challenge of NFV/Telco Cloud is the latency and process time between the various elements or functions.

A virtualized network function, or VNF, may consist of one or more virtual machines running different software and processes, on top of standard high-volume servers, switches and storage devices, or even cloud computing infrastructure, instead of having custom hardware appliances for each network function. Examples of VNF being MME, IMS, firewall, gateway, Controller, CPE, Antivirus, Video Optimizer etc.,

Framework

The NFV framework consists of three components:
• Virtualized network functions (VNFs) are software implementations of network functions that can be deployed on a network functions virtualization infrastructure (NFVI).

• Network functions virtualization infrastructure (NFVI) is the totality of all hardware and software components that build the environment where VNFs are deployed. The NFV infrastructure can span several locations. The network providing connectivity between these locations is considered as part of the NFV infrastructure.

• Network functions virtualization management and orchestration architectural framework (NFV-MANO Architectural Framework) is the collection of all functional blocks, data repositories used by these blocks, and reference points and interfaces through which these functional blocks exchange information for the purpose of managing and orchestrating NFVI and VNFs. It is also useful to manage multiple cloud instances and adding specific Telco services, such as better High Availability. The Software Defined Network Management is optional.

The above components form the framework of a NFV system and is equivalent to Telco cloud composition. Refer to the description of the same in the below picture.

Values of NFV

NFV is flexible, cost-effective, scalable, and secure. With these benefits, NFV addresses several trends shaping service provider networks.
•Flexibility: Operators looking to quickly deploy new services require a much more flexible and adaptable network — one that can be easily and quickly installed and provisioned.

•Cost: Cost is a top consideration for any operator or service provider these days. Cost is also reflected in operation expenditure,i.e, how easy it is to deploy and maintain services in the network.

•Scalability: To adapt quickly to users’ changing needs and provide new services, operators must be able to scale their network architecture across multiple servers, rather than being limited by what a single box can do.

•Security: Security has been, and continues to be, a major challenge in networking. Operators want to be able to provision and manage the network while allowing their customers to run their own virtual space and firewall securely within the network.

•Virtualization in another service provider network: To meet customers’ needs better, service providers want the ability to substantiate their service anywhere in the world using virtualization.

•Elasticity: To meet the increased traffic demand, operators must have applications that support real time scalability.

Software Defined Network(SDN)

A set of network principles where the data and control planes are totally seperated and controlled through APIs.In simple words,SDN technology is a novel approach to cloud computing that facilitates network management and enables programmatically efficient network configuration in order to improve network performance and monitoring.

The control plane consists of one or more controllers which are considered as the brain of SDN network where the whole intelligence is incorporated. However, the intelligence centralization has its own drawbacks when it comes to security, scalability and elasticity and this is the main issue of SDN.

In contrast to NFV which we had gone through earlier which was about making network function scalable, SDN is all about making network connection scalable.Example of SDN is Nuage in case of Nokia.

SDN and Cloud computing:
Whereas SDN is an architecture for a programmable network; OpenStack, Eucalyptus, vCloud Air, and Apache CloudStack are architectures for programmable clouds (i.e. network, memory, i/o, and storage). Programmable cloud compute systems may or may not use SDN.

OpenStack is a Cloud Management System which is just a facade that provides a uniform API for provisioning Compute, Network, Storage in a DataCenter. There are different plugins for each of these areas that can plugin into an OpenStack deployment and do the real provisioning work underneath.

Open DayLight is a SDN controller that provisions the network policies as specified and sends that information to the HYpervisor.
OpenFlow is the protocol used to program the Hypervisor vSwitches( which traffic to send where etc) and is the protocol via which an SDN controller communicates with the hypervisors.
OpenVSwitch is the implementation of a virtual switch in the Hypervisor that exposes OpenFlow protocol for flow information and uses the so called information provided via this protocol to make packet forwarding decisions.

ETSI-MANO Model

The Telco cloud poses a major interoperability challenge. To asssure interoperability, a first step would be to define standard interfaces for the control of the cloud.In November 2012, ETSI was selected to be the standard for NFV. ETSI NFV ISG group was formed subsequently which consists of 300 companies.

A traditional network needs just one management system i.e. an EMS (or an NMS) or at most supported by an OSS/BSS.
The NFV network, on the other hand, needs multiple managers i.e. a VIM Manager, a VNF Manager and an Orchestrator.And, if they are not enough, there is also the traditional EMS and OSS/BSS. That is, five different management systems.

ETSI is the pioneer and the only standards body that has done considerable work on defining the architecture and frame work of NFV.So it is worthwhile, understanding MANO by understanding the ETSI model.MANO acts as the heart and brain of NFV architecture and understanding it will clarify the complete NFV picture.This will help in understanding and benchmarking any vendor’s NFV solution with reference to the ETSI model.

The supervision and management block, NFV MANO is broken up into three functional sub blocks:
•NFV Orchestrator: Responsible for on-boarding of new network services (NS) and virtual network function (VNF) packages; NS lifecycle management; global resource management; validation and authorization of network functions virtualization infrastructure (NFVI) resource requests

•VNF Manager: Oversees lifecycle management of VNF instances; coordination and adaptation role for configuration and event reporting between NFVI and E/NMS. VNFM also does the FCAPS of the VNF but only for the virtual part.

•Virtualized Infrastructure Manager (VIM): Controls and manages the NFVI compute, storage, and network resources

The infrastructure and network functions user plane on the left consists of the OSS/BSS, EM, VNF and NFVI.

OSS/BSS includes collection of systems/applications that a service provider uses to operate its business.NFV is supposed to work in coordination with OSS/BSS.
Operation System Support(OSS) deals with network management, fault management, configuration management and service management.On the other hand, Business Support System(BSS) deals with customer management, product management and order management. The existing OSS/BBS, can value add the NFV MANO by offering additional functions if they are not supported by a certain implementation of NFV MANO.

EM is not part of the MANO, however it has important role to play.Element Management is responsible for the FCAPS (Fault, Configuration, Accounting, Performance and Security management) for the functional part of the VNF. The VNF below the EM refers to the services elements.

Finally, the NFVI consists of physical components like the servers and storage, virtual resources like VMs and software resources like the hypervisor in NFV environment. NFVI is not part of the NFV MANO architecture but is part of the NFV solution.

Sources : 
Workplace & General Learning

When we listen to the words Virtualization and cloud computing, we may think that both are similar but they are completely different concepts. In order to achieve capital expenditure or CAPEX savings, virtualization was introduced.Virtualization software makes it possible to run multiple instances of operating systems and multiple applications on the same server at the same time. It enables businesses to reduce IT costs while increasing the efficiency, utilization and flexibility of their existing computer hardware.

Virtualization is software that manipulates hardware, while cloud computing refers to a service that results from that manipulation. Theoritically, cloud service can be offered based only on physical server without virtualization.This would result in providing induviual servers as a service which would be sub efficient compared to the service with virtualization.

In order to achieve operational expenditure or OPEX savings and increase efficiency of infrastructure, cloud service was introduced through automation, standardization and scale.Thus we moved from pure virtualization to introducing cloud stack/layer between application and virtualized hardware.

Let’s dig deeper into each of the topics now;

1.  Virtualization

Virtualization is commonly hypervisor-based. The hypervisor isolates operating systems and applications from the underlying computer hardware so the host machine can run multiple virtual machines (VM) as guests that share the system’s physical compute resources, such as processor cycles, memory space, network bandwidth and so on.

Type 1 hypervisors, sometimes called bare-metal hypervisors, run directly on top of the host system hardware. Bare-metal hypervisors offer high availability and resource management. Their direct access to system hardware enables better performance, scalability and stability. Examples of type 1 hypervisors include Microsoft Hyper-V, Citrix XenServer and VMware ESXi.

A type 2 hypervisor, also known as a hosted hypervisor, is installed on top of the host operating system, rather than sitting directly on top of the hardware as the type 1 hypervisor does. Each guest OS or VM runs above the hypervisor. The convenience of a known host OS can ease system configuration and management tasks. However, the addition of a host OS layer can potentially limit performance and expose possible OS security flaws. Examples of type 2 hypervisors include VMware Workstation, KVM, EMU Vmware and Oracle VM VirtualBox.

The main alternative to hypervisor-based virtualization is containerization. Container virtualization (often referred as operating system virtualization) is more than just a different kind of hypervisor. Containers use the host operating system as their base, and not the hypervisor. Rather than virtualizing the hardware (which requires full virtualized operating system images for each guest), containers virtualize the OS itself, sharing the host OS kernel and its resources with both the host and other containers.

2. Cloud Computing

It is the method of building and providing on demand resources (memory, processor etc.,) over IP networks using data centers. Cloud computing enables companies/users to consume a compute resource, such as a virtual machine (VM), storage or an application, as a utility rather than having to build and maintain computing infrastructures in house. In other words, Cloud lets you trade CAPEX for OPEX ,i.e, you can pay only when you consume resources and on only how much you consume. Examples : AWS, Google docs/drive/app, Azure etc.

Some of the benefits of cloud computing:
• Self-service provisioning: End users can spin up compute resources for almost any type of workload on demand. This eliminates the traditional need for IT administrators to provision and manage compute resources.

• Elasticity: Companies can scale up as computing needs increase and scale down again as demands decrease. This eliminates the need for massive investments in local infrastructure, which may or may not remain active.

• Pay per use: Compute resources are measured at a granular level, enabling users to pay only for the resources and workloads they use.

• Migration flexibility: Organizations can move certain workloads to or from the cloud — or to different cloud platforms — as desired or automatically for better cost savings or to use new services as they emerge.

There are three main types of cloud service:

• Software as a Service (SaaS)
It is a software distribution model in which applications are hosted by a vendor or service provider and made available to customers over a network, typically the Internet.The consumer does not manage or control the underlying cloud infrastructure.Examples: Google Apps, Micorsoft Office 365, Gmail, facebook.

• Platform as a Service (PaaS)
It is a paradigm for delivering operating systems and associated services like web services etc over the Internet without downloads or installation.The consumer does not manage or control the underlying cloud infrastructure like servers, OS etc, but has control over the deployed applications and possibly configuration settings for the application-hosting environment.Examples: Tomcat, Google App engine, Apache Stratos.

• Infrastructure as a Service (IaaS)
It involves outsourcing the physical or Virtual machines used to support operations, including storage, hardware, servers and networking components.The consumer does not manage or control the underlying cloud infrastructure but has control over OS, storage and deployed applications.Examples: AWS, Microsoft Azure,Google compute Engine.

Let me sum up the service models as follows;

The cloud service can be deployed based on a particular model. A cloud deployment model represents a specific type of cloud environment, primarily distinguished by ownership, size, and access.

Some of the common cloud deployment models:

• Public Cloud
The most common and well-known deployment model is Public Cloud. A Public Cloud is a huge data centre that offers the same services to all its users. The services are accessible for everyone,i.e, open access and much used for the consumer segment. Examples of public services are AWS, Google, Yahoo, Office365 etc., For consumers, Public Cloud offerings are usually free of charge, for professionals there is usually a per-per-use (or user) pricing model. The Public Cloud is always hosted by a professional Cloud supplier.

• Private Cloud
A private cloud is cloud infrastructure that only members of your organization can utilize. It is typically owned and managed by the organization itself and is hosted on premises but it could also be managed by a third party in a secure datacenter. This deployment model is best suited for organizations that deal with sensitive data and/or are required to uphold certain security standards by various regulations.Example of Private cloud are Amazon VPC(Virtual Private Cloud), VMware Cloud Infrastructure suite.

• Community Cloud
This is the model where the cloud infrastructure is shared by several organizations and supports a specific community that has shared concerns (e.g., mission, security requirements, policy, and compliance considerations). It may be managed by the organizations or a third party and may exist on premise or off premise. Example of community cloud being Google Apps for the government,Microsoft Government Community Cloud.

• Hybrid Cloud
This type of cloud infrastructure assumes that you are hosting your system both on private and public cloud. One use case might be regulation requiring data to be stored in a locked down private data center but have the application processing parts available on the public cloud and talking to the private components over a secure tunnel.

Another example is hosting most of the system inside a private cloud and having a clone of the system on the public cloud to allow for rapid scaling and accommodating bursts of new usage that would otherwise not be possible on the private cloud.To sum it up, we can say that it is a combination of public, private or community cloud models. Examples of Hybrid cloud being Windows Azure, VMware vCloud.

• Virtual Private Cloud
Virtual private clouds offer scalable compute resources similar to that of public clouds, but in a more controlled environment.To be more specific, a virtual private cloud (VPC) is the logical division of a service provider’s public cloud multi-tenant architecture to support private cloud computing in a public cloud environment. Public cloud providers like AWS, Google, Microsoft offer the possibility of setting up a VPC using virtual networks.

You can get the overall picture of the various deployment models as follows;

Check out my other blogs for further reading.,

Sources :
Online Learning