Virtual appliance

Last updated

A virtual appliance is a pre-configured virtual machine image, ready to run on a hypervisor; virtual appliances are a subset of the broader class of software appliances. Installation of a software appliance on a virtual machine and packaging that into an image creates a virtual appliance. Like software appliances, virtual appliances are intended to eliminate the installation, configuration and maintenance costs associated with running complex stacks of software.

Contents

A virtual appliance is not a complete virtual machine platform, but rather a software image containing a software stack designed to run on a virtual machine platform which may be a Type 1 or Type 2 hypervisor.

File formats

Virtual appliances are provided to the user or customer as files, via either electronic downloads or physical distribution. The file format most commonly used is the Open Virtualization Format (OVF). It may also be distributed as Open Virtual Appliance (OVA), the .ova file format is interchangeable with .ovf. The Distributed Management Task Force (DMTF) publishes the OVF specification documentation. [1] Most virtualization platforms, including those from VMware, Microsoft, Oracle, and Citrix, can install virtual appliances from an OVF file. [2]

Grid computing

Virtualization solves a key problem in the grid computing arena – namely, the reality that any sufficiently large grid will inevitably consist of a wide variety of heterogeneous hardware and operating system configurations. Adding virtual appliances into the picture allows for extremely rapid provisioning of grid nodes and importantly, cleanly decouples the grid operator from the grid consumer by encapsulating all knowledge of the application within the virtual appliance.

Infrastructure as a service

Virtual appliances are critical resources in infrastructure as a service cloud computing. The file format of the virtual appliance is the concern of the cloud provider and usually not relevant to the cloud user even though the cloud user may be the owner of the virtual appliance. However, challenges may arise with the transfer of virtual appliance ownership or transfer of virtual appliances between cloud data centers. In this case, virtual appliance copy or export/import features can be used to overcome this problem. [3]

Software as a service

With the rise of virtualization as a platform for hosted services provision, virtual appliances have come to provide a direct route for traditional on-premises applications to be rapidly redeployed in a software as a service (SaaS) mode – without requiring major application re-architecture for multi-tenancy. By decoupling the hardware and operating system infrastructure provider from the application stack provider, virtual appliances allow economies of scale on the one side to be leveraged by the economy of simplicity on the other. Traditional approaches to SaaS, such as that touted by Salesforce.com, leverage shared infrastructure by forcing massive change and increased complexity on the software stack.

A concrete example of the virtual appliances approach to delivering SaaS is the Amazon Elastic Compute Cloud (EC2)—a grid of Xen hypervisor nodes coupled with the availability of pre-packaged virtual appliances in the Amazon Machine Image format. Amazon EC2 reduces the cost-barrier to the point where it becomes feasible to have each customer of the hosted service provisioned with their own virtual appliance instance(s) rather than forcing them to share common instances. Prior to EC2, single-tenant hosted models were too expensive, leading to the failure of many early ASP offerings.

Furthermore, in contrast to the multi-tenancy approaches to SaaS, a virtual appliance can also be deployed on-premises for customers that need local network access to the running application, or have security requirements that a third-party hosting model does not meet. The underlying virtualization technology also allows for rapid movement of virtual appliances instances between physical execution environments. Traditional approaches to SaaS fix the application in place on the hosted infrastructure.

See also

Related Research Articles

Utility computing, or computer utility, is a service provisioning model in which a service provider makes computing resources and infrastructure management available to the customer as needed, and charges them for specific usage rather than a flat rate. Like other types of on-demand computing, the utility model seeks to maximize the efficient use of resources and/or minimize associated costs. Utility is the packaging of system resources, such as computation, storage and services, as a metered service. This model has the advantage of a low or no initial cost to acquire computer resources; instead, resources are essentially rented.

A software appliance is a software application combined with just enough operating system (JeOS) to run optimally on industry-standard hardware or in a virtual machine. It is a software distribution or firmware that implements a computer appliance.

<span class="mw-page-title-main">Desktop virtualization</span> Software technology

Desktop virtualization is a software technology that separates the desktop environment and associated application software from the physical client device that is used to access it.

Infrastructure as a service (IaaS) is a cloud computing service model by means of which computing resources are supplied by a cloud services provider. The IaaS vendor provides the storage, network, servers, and virtualization. This service enables users to free themselves from maintaining an on-premises data center. The IaaS provider is hosting these resources in either the public cloud, the private cloud, or the hybrid cloud.

Open Virtualization Format (OVF) is an open standard for packaging and distributing virtual appliances or, more generally, software to be run in virtual machines.

<span class="mw-page-title-main">Virtualization</span> Methods for dividing computing resources

In computing, virtualization (v12n) is a series of technologies that allows dividing of physical computing resources into a series of virtual machines, operating systems, processes or containers.

<span class="mw-page-title-main">Bitnami</span> Software library

Bitnami is a library of installers or software packages for web applications and software stacks as well as virtual appliances. Bitnami is sponsored by Bitrock, a company founded in 2003 in Seville, Spain by Daniel Lopez Ridruejo and Erica Brescia. Bitnami stacks are used for installing software on Linux, Windows, macOS and Solaris. VMware acquired Bitrock, along with its two largest properties, Bitnami and InstallBuilder, on May 15, 2019.

<span class="mw-page-title-main">Cloud computing</span> Form of shared internet-based computing

Cloud computing is the on-demand availability of computer system resources, especially data storage and computing power, without direct active management by the user. Large clouds often have functions distributed over multiple locations, each of which is a data center. Cloud computing relies on sharing of resources to achieve coherence and typically uses a pay-as-you-go model, which can help in reducing capital expenses but may also lead to unexpected operating expenses for users.

<span class="mw-page-title-main">TurnKey Linux Virtual Appliance Library</span> Open-Source virtual appliance library

The TurnKey Linux Virtual Appliance Library is a free open-source software project which develops a range of Debian-based pre-packaged server software appliances. Turnkey appliances can be deployed as a virtual machine, in cloud computing services such as Amazon Web Services or installed in physical computers.

<span class="mw-page-title-main">OpenStack</span> Cloud computing software

OpenStack is a free, open standard cloud computing platform. It is mostly deployed as infrastructure-as-a-service (IaaS) in both public and private clouds where virtual servers and other resources are made available to users. The software platform consists of interrelated components that control diverse, multi-vendor hardware pools of processing, storage, and networking resources throughout a data center. Users manage it either through a web-based dashboard, through command-line tools, or through RESTful web services.

Deltacloud is an application programming interface (API) developed by Red Hat and the Apache Software Foundation that abstracts differences between cloud computing implementations. It was created in 2009.

<span class="mw-page-title-main">OpenNebula</span> Cloud-computing platform for managing heterogeneous distributed infrastructure

OpenNebula is an open source cloud computing platform for managing heterogeneous data center, public cloud and edge computing infrastructure resources. OpenNebula manages on-premises and remote virtual infrastructure to build private, public, or hybrid implementations of Infrastructure as a Service and multi-tenant Kubernetes deployments. The two primary uses of the OpenNebula platform are data center virtualization and cloud deployments based on the KVM hypervisor, LXD/LXC system containers, and AWS Firecracker microVMs. The platform is also capable of offering the cloud infrastructure necessary to operate a cloud on top of existing VMware infrastructure. In early June 2020, OpenNebula announced the release of a new Enterprise Edition for corporate users, along with a Community Edition. OpenNebula CE is free and open-source software, released under the Apache License version 2. OpenNebula CE comes with free access to patch releases containing critical bug fixes but with no access to the regular EE maintenance releases. Upgrades to the latest minor/major version is only available for CE users with non-commercial deployments or with significant open source contributions to the OpenNebula Community. OpenNebula EE is distributed under a closed-source license and requires a commercial Subscription.

Wakame-vdc is an IaaS cloud computing framework, facilitating the provisioning and management of a heterogeneous virtualized infrastructure. Wakame-vdc virtualizes the entire data center; servers, storage, and networking. Wakame-vdc is managed via a native Web Interface, the Wakame-vdc CLI, or the powerful Wakame-vdc API.

Nimbula was a computer software company that existed from 2008 to 2017. It developed software for the implementation of public and private cloud computing environments.

A cloud database is a database that typically runs on a cloud computing platform and access to the database is provided as-a-service. There are two common deployment models: users can run databases on the cloud independently, using a virtual machine image, or they can purchase access to a database service, maintained by a cloud database provider. Of the databases available on the cloud, some are SQL-based and some use a NoSQL data model.

HP CloudSystem is a cloud infrastructure from Hewlett Packard Enterprise (HPE) that combines storage, servers, networking and software.

<span class="mw-page-title-main">Abiquo Enterprise Edition</span>

Abiquo Hybrid Cloud Management Platform is a web-based cloud computing software platform developed by Abiquo. Written entirely in Java, it is used to build, integrate and manage public and private clouds in homogeneous environments. Users can deploy and manage servers, storage system and network and virtual devices. It also supports LDAP integration.

Software-defined storage (SDS) is a marketing term for computer data storage software for policy-based provisioning and management of data storage independent of the underlying hardware. Software-defined storage typically includes a form of storage virtualization to separate the storage hardware from the software that manages it. The software enabling a software-defined storage environment may also provide policy management for features such as data deduplication, replication, thin provisioning, snapshots and backup.

Cloud Infrastructure Management Interface (CIMI) is an open standard API specification for managing cloud infrastructure.

Virtuozzo is a software company that develops virtualization and cloud management software for cloud computing providers, managed services providers and internet hosting service providers. The company's software enables service providers to offer Infrastructure as a service, Container-as-a-Service, Platform as a service, Kubernetes-as-a-Service, WordPress-as-a-Service and other solutions.

References

  1. ↑ "OVF 1.1 Specification" (PDF).
  2. ↑ "VirtualBox changelog" . Retrieved 2009-04-13.
  3. ↑ Wu C F, Wang Y S, Liu G N, Amies, A, 2012, Create solutions on IBM SmartCloud Enterprise: Transfer image assets between different accounts IBM developerWorks, June 6.

Further reading

This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.