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A computer appliance is a computer system with a combination of hardware, software, or firmware that is specifically designed to provide a particular computing resource. Such devices became known as appliances because of the similarity in role or management to a home appliance, which are generally closed and sealed, and are not serviceable by the user or owner. The hardware and software are delivered as an integrated product and may even be pre-configured before delivery to a customer, to provide a turn-key solution for a particular application. Unlike general purpose computers, appliances are generally not designed to allow the customers to change the software and the underlying operating system, or to flexibly reconfigure the hardware.
Another form of appliance is the virtual appliance, which has similar functionality to a dedicated hardware appliance, but is distributed as a software virtual machine image for a hypervisor-equipped device.
Traditionally, software applications run on top of a general-purpose operating system, which uses the hardware resources of the computer (primarily memory, disk storage, processing power, and networking bandwidth) to meet the computing needs of the user. The main issue with the traditional model is related to complexity. It is complex to integrate the operating system and applications with a hardware platform, and complex to support it afterwards.
By tightly constraining the variations of the hardware and software, the appliance becomes easily deployable, and can be used without nearly as wide (or deep) IT knowledge. Additionally, when problems and errors appear, the supporting staff very rarely needs to explore them deeply to understand the matter thoroughly. The staff needs merely training on the appliance management software to be able to resolve most of problems.
In all forms of the computer appliance model, customers benefit from easy operations. The appliance has exactly one combination of hardware and operating system and application software, which has been pre-installed at the factory. This prevents customers from needing to perform complex integration work, and dramatically simplifies troubleshooting. In fact, this "turnkey operation" characteristic is the driving benefit that customers seek when purchasing appliances.
To be considered an appliance, the (hardware) device needs to be integrated with software, and both are supplied as a package.[ citation needed ] This distinguishes appliances from "home grown" solutions, or solutions requiring complex implementations by integrators or value-added resellers (VARs).
The appliance approach helps to decouple the various systems and applications, for example in the data center. Once a resource is decoupled, in theory it can be also centralized to become shared among many systems, centrally managed and optimized, all without requiring changes to any other system.
The major[ citation needed ] disadvantage of deploying a computer appliance is that since they are designed to supply a specific resource, they most often include a customized operating system running over specialized hardware, neither of which are likely to be compatible with the other systems previously deployed. Customers lose flexibility.
One may believe that a proprietary embedded operating system, or operating system within an application, can make the appliance much more secure from common cyber attacks. However, the opposite is true. Security by obscurity is a poor security decision, and appliances are often plagued by security issues as evidenced by the proliferation of IoT devices. [1]
The variety of computer appliances reflects the wide range of computing resources they provide to applications. Some examples:
Aside from its deployment within data centers, many computer appliances are directly used by the general public. These include:[ citation needed ]
Consumer uses stress the need for an appliance to have easy installation, configuration, and operation, with little or no technical knowledge being necessary.
The world of industrial automation has been rich in appliances. These appliances have been hardened to withstand temperature and vibration extremes. These appliances are also highly configurable, enabling customization to meet a wide variety of applications. The key benefits of an appliance in automation are:
Types of automation appliances:[ citation needed ]
This section possibly contains original research .(September 2011) |
There are several design patterns adopted by computer appliance vendors, a few of which are shown below. Since the whole concept of an appliance rests on keeping such implementation details away from the end user, it is difficult to match these patterns to specific appliances, particularly since they can and do change without affecting external capabilities or performance.
Sometimes, these techniques are mixed. For example, a VPN appliance might contain a limited access software firewall running on Linux, with an encryption ASIC to speed up VPN access.
Some computer appliances use solid state storage, while others use a hard drive to load an operating system. Again, the two methods might be mixed—an ASIC print server might allow an optional hard drive for job queueing, or a Linux-based device may encode Linux in firmware, so that a hard drive is not needed to load the operating system. [5]
In computing, firmware is software that provides low-level control of computing device hardware. For a relatively simple device, firmware may perform all control, monitoring and data manipulation functionality. For a more complex device, firmware may provide relatively low-level control as well as hardware abstraction services to higher-level software such as an operating system.
An embedded system is a computer system—a combination of a computer processor, computer memory, and input/output peripheral devices—that has a dedicated function within a larger mechanical or electronic system. It is embedded as part of a complete device often including electrical or electronic hardware and mechanical parts. Because an embedded system typically controls physical operations of the machine that it is embedded within, it often has real-time computing constraints. Embedded systems control many devices in common use. In 2009, it was estimated that ninety-eight percent of all microprocessors manufactured were used in embedded systems.
Appliance may refer to:
Network-attached storage (NAS) is a file-level computer data storage server connected to a computer network providing data access to a heterogeneous group of clients. The term "NAS" can refer to both the technology and systems involved, or a specialized device built for such functionality.
A hypervisor, also known as a virtual machine monitor (VMM) or virtualizer, is a type of computer software, firmware or hardware that creates and runs virtual machines. A computer on which a hypervisor runs one or more virtual machines is called a host machine, and each virtual machine is called a guest machine. The hypervisor presents the guest operating systems with a virtual operating platform and manages the execution of the guest operating systems. Unlike an emulator, the guest executes most instructions on the native hardware. Multiple instances of a variety of operating systems may share the virtualized hardware resources: for example, Linux, Windows, and macOS instances can all run on a single physical x86 machine. This contrasts with operating-system–level virtualization, where all instances must share a single kernel, though the guest operating systems can differ in user space, such as different Linux distributions with the same kernel.
A virtual storage area network is a logical representation of a physical storage area network (SAN). A VSAN abstracts the storage-related operations from the physical storage layer, and provides shared storage access to the applications and virtual machines by combining the servers' local storage over a network into a single or multiple storage pools.
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.
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.
PikeOS is a commercial hard real-time operating system (RTOS) which features a separation kernel-based hypervisor. This hypervisor supports multiple logical partition types for various operating systems (OS) and applications, each referred to as a GuestOS. PikeOS is engineered to support the creation of certifiable smart devices for the Internet of Things (IoT), ensuring compliance with industry standards for quality, safety, and security across various sectors. In instances where memory management units (MMU) are not present but memory protection units (MPU) are available on controller-based systems, PikeOS for MPU is designed for critical real-time applications and provides up-to-standard safety and security.
The following is about Virtualization development. In computing, virtualization is the use of a computer to simulate another computer. Through virtualization, a host simulates a guest by exposing virtual hardware devices, which may be done through software or by allowing access to a physical device connected to the machine.
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.
Hardware virtualization is the virtualization of computers as complete hardware platforms, certain logical abstractions of their componentry, or only the functionality required to run various operating systems. Virtualization hides the physical characteristics of a computing platform from the users, presenting instead an abstract computing platform. At its origins, the software that controlled virtualization was called a "control program", but the terms "hypervisor" or "virtual machine monitor" became preferred over time.
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.
In computing, network virtualization is the process of combining hardware and software network resources and network functionality into a single, software-based administrative entity, a virtual network. Network virtualization involves platform virtualization, often combined with resource virtualization.
A virtual security appliance is a computer appliance that runs inside virtual environments. It is called an appliance because it is pre-packaged with a hardened operating system and a security application and runs on a virtualized hardware. The hardware is virtualized using hypervisor technology delivered by companies such as VMware, Citrix and Microsoft. The security application may vary depending on the particular network security vendor. Some vendors such as Reflex Systems have chosen to deliver Intrusion Prevention technology as a Virtualized Appliance, or as a multifunctional server vulnerability shield delivered by Blue Lane. The type of security technology is irrelevant when it comes to the definition of a Virtual Security Appliance and is more relevant when it comes to the performance levels achieved when deploying various types of security as a virtual security appliance. Other issues include visibility into the hypervisor and the virtual network that runs inside.
In computing, virtualization or virtualisation in British English is the act of creating a virtual version of something at the same abstraction level, including virtual computer hardware platforms, storage devices, and computer network resources.
A virtual firewall (VF) is a network firewall service or appliance running entirely within a virtualized environment and which provides the usual packet filtering and monitoring provided via a physical network firewall. The VF can be realized as a traditional software firewall on a guest virtual machine already running, a purpose-built virtual security appliance designed with virtual network security in mind, a virtual switch with additional security capabilities, or a managed kernel process running within the host hypervisor.
StarWind Software, Inc. is a privately held Beverly, Massachusetts-based computer software and hardware appliance company specializing in storage virtualization and software-defined storage.
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.
Qubes OS is a security-focused desktop operating system that aims to provide security through isolation. Isolation is provided through the use of virtualization technology. This allows the segmentation of applications into secure virtual machines called qubes. Virtualization services in Qubes OS are provided by the Xen hypervisor.