Memory ballooning allows you to have your guest dynamically change it’s memory usage by evicting unused memory during runtime. This is a useful feature because it reduces the impact your guest can have on memory usage of your host by giving up unused memory back to the host.
Showing posts with label Virtualization. Show all posts
Showing posts with label Virtualization. Show all posts
What is cloud computing
Cloud computing is a general term for anything that involves delivering hosted services over the Internet. These services are broadly divided into some categories: Infrastructure-as-a-Service (IaaS), Platform-as-a-Service (PaaS) and Software-as-a-Service (SaaS) and Hardware as a Service (HaaS). The name cloud computing was inspired by the cloud symbol that's often used to represent the Internet in flowcharts and diagrams.
A cloud service has distinct characteristics that differentiate it from traditional hosting. It is sold on demand, typically by the minute or the hour; it is elastic -- a user can have as much or as little of a service as they want at any given time; and the service is fully managed by the provider (the consumer needs nothing but a personal computer and Internet access). Significant innovations in virtualization and distributed computing, as well as improved access to high-speed Internet and a weak economy, have accelerated interest in cloud computing.
A cloud can be private or public. A public cloud sells services to anyone on the Internet. (Currently, Amazon Web Services is the largest public cloud provider.) A private cloud is a proprietary network or a data center that supplies hosted services to a limited number of people. When a service provider uses public cloud resources to create their private cloud, the result is called a virtual private cloud. Private or public, the goal of cloud computing is to provide easy, scalable access to computing resources and IT services.
Hardware as a Service (HaaS) is a service provision model for hardware that is defined differently in managed services and grid computing contexts. In managed services, HaaS is similar to licensing. In grid computing, HaaS is a pay as you use model.
Infrastructure-as-a-Service(IaaS) like Amazon Web Services provides virtual server instanceAPI) to start, stop, access and configure their virtual servers and storage. In the enterprise, cloud computing allows a company to pay for only as much capacity as is needed, and bring more online as soon as required
Platform-as-a-service(PaaS) in the cloud is defined as a set of software and product development tools hosted on the provider's infrastructure. Developers create applications on the provider's platform over the Internet. PaaS providers may use APIs, website portals or gateway software installed on the customer's computer. Force.com, (an outgrowth of Salesforce.com) and GoogleApps are examples of PaaS.
software-as-a-service(SaaS) in this cloud model, the vendor supplies the hardware infrastructure, the software product and interacts with the user through a front-end portal. Services can be anything from Web-based email to inventory control and database processing. Because the service provider hosts both the application and the data, the end user is free to use the service from anywhere.
A cloud service has distinct characteristics that differentiate it from traditional hosting. It is sold on demand, typically by the minute or the hour; it is elastic -- a user can have as much or as little of a service as they want at any given time; and the service is fully managed by the provider (the consumer needs nothing but a personal computer and Internet access). Significant innovations in virtualization and distributed computing, as well as improved access to high-speed Internet and a weak economy, have accelerated interest in cloud computing.
A cloud can be private or public. A public cloud sells services to anyone on the Internet. (Currently, Amazon Web Services is the largest public cloud provider.) A private cloud is a proprietary network or a data center that supplies hosted services to a limited number of people. When a service provider uses public cloud resources to create their private cloud, the result is called a virtual private cloud. Private or public, the goal of cloud computing is to provide easy, scalable access to computing resources and IT services.
Hardware as a Service (HaaS) is a service provision model for hardware that is defined differently in managed services and grid computing contexts. In managed services, HaaS is similar to licensing. In grid computing, HaaS is a pay as you use model.
Infrastructure-as-a-Service(IaaS) like Amazon Web Services provides virtual server instanceAPI) to start, stop, access and configure their virtual servers and storage. In the enterprise, cloud computing allows a company to pay for only as much capacity as is needed, and bring more online as soon as required
Platform-as-a-service(PaaS) in the cloud is defined as a set of software and product development tools hosted on the provider's infrastructure. Developers create applications on the provider's platform over the Internet. PaaS providers may use APIs, website portals or gateway software installed on the customer's computer. Force.com, (an outgrowth of Salesforce.com) and GoogleApps are examples of PaaS.
software-as-a-service(SaaS) in this cloud model, the vendor supplies the hardware infrastructure, the software product and interacts with the user through a front-end portal. Services can be anything from Web-based email to inventory control and database processing. Because the service provider hosts both the application and the data, the end user is free to use the service from anywhere.
What is Hypervisor
A hypervisor, also called a virtual machine manager, is a program that allows multiple operating systems to share a single hardware host. Each operating system appears to have the host's processor, memory, and other resources all to itself. However, the hypervisor is actually controlling the host processor and resources, allocating what is needed to each operating system in turn and making sure that the guest operating systems (called virtual mahines) cannot disrupt each other.
Type 1 hypervisor runs directly on the hardware.
Type 2 hypervisor runs on another operating system, such as Linux.
Major Hypervisors
• Xen
• KVM
• VMware ESX
• Microsoft Hyper-V
• PowerVM
• Logical Domains / Oracle VM
Type 1 hypervisor runs directly on the hardware.
Type 2 hypervisor runs on another operating system, such as Linux.
Major Hypervisors
• Xen
• KVM
• VMware ESX
• Microsoft Hyper-V
• PowerVM
• Logical Domains / Oracle VM
Virtualization
Virtualization:Industry moving from concept of buying to leasing
Software as a Service ( SaaS)
Platform as a Service (PaaS)
Hardware as a Service ( HaaS)
Virtualization is the creation of a virtual (rather than actual) version of something, such as an operating system, a server, a storage device or network resources.
Allows to create multiple virtual machines on a single physical server
Allows to run multiple operating System environment in a single Physical server.
Better utilization of Hardware resources - CPU, Memory
Reduces the need for huge no of Physical servers
There are several different forms of virtualization that need to be understood as a basis for making the right technology choice.
* Network virtualization is a method of combining the available resources in a network by splitting up the available bandwidth into channels, each of which is independent from the others, and each of which can be assigned (or reassigned) to a particular server or device in real time. The idea is that virtualization disguises the true complexity of the network by separating it into manageable parts, much like your partitioned hard drive makes it easier to manage your files.
* Storage virtualization is the pooling of physical storage from multiple network storage devices into what appears to be a single storage device that is managed from a central console. Storage virtualization is commonly used in storage area networks (SANs).
* Server virtualization is the masking of server resources (including the number and identity of individual physical servers, processors, and operating systems) from server users. The intention is to spare the user from having to understand and manage complicated details of server resources while increasing resource sharing and utilization and maintaining the capacity to expand later.
* Server Hardware Virtualization. Also known as a hypervisor, Server Hardware Virtualization runs a very lightweight core operating system. The hypervisor can host independent virtual machines (VMs). This form of virtualization requires hardware that has embedded virtualization awareness capabilities. Since the hypervisor is very lightweight, there is little overhead in the system, which allows for more scalability in the virtual machines.
* Server Software Virtualization: An operating system, such as Windows Server® 2003 or Windows Server 2008, runs an application that is able to host virtual machines. Each virtual machine runs a completely separate operating system and application set.
* Presentation Virtualization: Centralized systems host multiple user sessions, and all processing is done on those host systems. The user sessions are isolated from each other. Only the presentation information, such as keyboard and mouse inputs, and video updates are sent between the client and the host system. The client can be a full Windows-based workstation or a Windows-based terminal device.
* Application Virtualization: An application is isolated from the underlying operating system by means of wrapper software that encapsulates it. This allows multiple applications that may have conflicting dynamic link libraries (DLLs) or other incompatibilities to run on the same machine without affecting each other.
* Desktop Virtualization: This is similar to Server Software Virtualization, but it runs on client systems such as Windows Vista®. The client operating system runs a virtualization application that hosts virtual machines. This is often used when a specific person needs to run one or a limited number of legacy applications on a legacy operating system.
Virtualization products
Linux
Linux virtualization users have two free, open source hypervisors to choose from: Xen and KVM.
VMware
VMware workstation
VMware Fusion ( MAC os)
VMware server ( GSX Server)
VMware ESX Server 4.0/4.0i & Vsphere
Microsoft
Microsoft Virtual PC
Microsoft Virtual Server
Hyper-V (This feature available only on Microsoft Windows Server 2008 )
Citrix
XEN Server
Virtualization environment
Host Machine - Physical server/Machine where Virtualization software deployed
Virtualization software : Software that allows to create, manage virtual machines & Virtual environment
Guest operating system : Operating system installed into virtual machine
Virtual Machine or VM :A machine is made up of Software files, provides Virtual hardware created by Virtualization software.A Virtual Machine will have Virtual Devices like Processor, Disk, Ethernet, Motherboard, VGA, etc..
Software as a Service ( SaaS)
Platform as a Service (PaaS)
Hardware as a Service ( HaaS)
Virtualization is the creation of a virtual (rather than actual) version of something, such as an operating system, a server, a storage device or network resources.
Allows to create multiple virtual machines on a single physical server
Allows to run multiple operating System environment in a single Physical server.
Better utilization of Hardware resources - CPU, Memory
Reduces the need for huge no of Physical servers
There are several different forms of virtualization that need to be understood as a basis for making the right technology choice.
* Network virtualization is a method of combining the available resources in a network by splitting up the available bandwidth into channels, each of which is independent from the others, and each of which can be assigned (or reassigned) to a particular server or device in real time. The idea is that virtualization disguises the true complexity of the network by separating it into manageable parts, much like your partitioned hard drive makes it easier to manage your files.
* Storage virtualization is the pooling of physical storage from multiple network storage devices into what appears to be a single storage device that is managed from a central console. Storage virtualization is commonly used in storage area networks (SANs).
* Server virtualization is the masking of server resources (including the number and identity of individual physical servers, processors, and operating systems) from server users. The intention is to spare the user from having to understand and manage complicated details of server resources while increasing resource sharing and utilization and maintaining the capacity to expand later.
* Server Hardware Virtualization. Also known as a hypervisor, Server Hardware Virtualization runs a very lightweight core operating system. The hypervisor can host independent virtual machines (VMs). This form of virtualization requires hardware that has embedded virtualization awareness capabilities. Since the hypervisor is very lightweight, there is little overhead in the system, which allows for more scalability in the virtual machines.
* Server Software Virtualization: An operating system, such as Windows Server® 2003 or Windows Server 2008, runs an application that is able to host virtual machines. Each virtual machine runs a completely separate operating system and application set.
* Presentation Virtualization: Centralized systems host multiple user sessions, and all processing is done on those host systems. The user sessions are isolated from each other. Only the presentation information, such as keyboard and mouse inputs, and video updates are sent between the client and the host system. The client can be a full Windows-based workstation or a Windows-based terminal device.
* Application Virtualization: An application is isolated from the underlying operating system by means of wrapper software that encapsulates it. This allows multiple applications that may have conflicting dynamic link libraries (DLLs) or other incompatibilities to run on the same machine without affecting each other.
* Desktop Virtualization: This is similar to Server Software Virtualization, but it runs on client systems such as Windows Vista®. The client operating system runs a virtualization application that hosts virtual machines. This is often used when a specific person needs to run one or a limited number of legacy applications on a legacy operating system.
Virtualization products
Linux
Linux virtualization users have two free, open source hypervisors to choose from: Xen and KVM.
VMware
VMware workstation
VMware Fusion ( MAC os)
VMware server ( GSX Server)
VMware ESX Server 4.0/4.0i & Vsphere
Microsoft
Microsoft Virtual PC
Microsoft Virtual Server
Hyper-V (This feature available only on Microsoft Windows Server 2008 )
Citrix
XEN Server
Virtualization environment
Host Machine - Physical server/Machine where Virtualization software deployed
Virtualization software : Software that allows to create, manage virtual machines & Virtual environment
Guest operating system : Operating system installed into virtual machine
Virtual Machine or VM :A machine is made up of Software files, provides Virtual hardware created by Virtualization software.A Virtual Machine will have Virtual Devices like Processor, Disk, Ethernet, Motherboard, VGA, etc..
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