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Diskless Shared-root Cluster
{{no footnotes, date=August 2016 A diskless shared-root cluster is a way to manage several machines at the same time. Instead of each having its own operating system (OS) on its local disk, there is only one image of the OS available on a server, and all the nodes use the same image. (SSI cluster = single-system image) The simplest way to achieve this is to use a NFS server, configured to host the generic boot image for the SSI cluster nodes. (pxe + dhcp + tftp + nfs) To ensure that there is no single point of failure, the NFS export for the boot-image should be hosted on a two node cluster. The architecture of a diskless computer cluster makes it possible to separate servers and storage array. The operating system as well as the actual reference data (userfiles, databases or websites) are stored competitively on the attached storage system in a centralized manner. Any server that acts as a cluster node can be easily exchanged by demand. The additional abstraction layer between s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Operating System
An operating system (OS) is system software that manages computer hardware and software resources, and provides common daemon (computing), services for computer programs. Time-sharing operating systems scheduler (computing), schedule tasks for efficient use of the system and may also include accounting software for cost allocation of Scheduling (computing), processor time, mass storage, peripherals, and other resources. For hardware functions such as input and output and memory allocation, the operating system acts as an intermediary between programs and the computer hardware, although the application code is usually executed directly by the hardware and frequently makes system calls to an OS function or is interrupted by it. Operating systems are found on many devices that contain a computerfrom cellular phones and video game consoles to web servers and supercomputers. , Android (operating system), Android is the most popular operating system with a 46% market share, followed ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Single-system Image
In distributed computing, a single system image (SSI) cluster is a cluster of machines that appears to be one single system. The concept is often considered synonymous with that of a distributed operating system, but a single image may be presented for more limited purposes, just job scheduling for instance, which may be achieved by means of an additional layer of software over conventional operating system images running on each node. The interest in SSI clusters is based on the perception that they may be simpler to use and administer than more specialized clusters. Different SSI systems may provide a more or less complete illusion of a single system. Features of SSI clustering systems Different SSI systems may, depending on their intended usage, provide some subset of these features. Process migration Many SSI systems provide process migration. Processes may start on one node and be moved to another node, possibly for resource balancing or administrative reasons.for example ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Single Point Of Failure
A single point of failure (SPOF) is a part of a system that would Cascading failure, stop the entire system from working if it were to fail. The term single point of failure implies that there is not a backup or redundant option that would enable the system to continue to function without it. SPOFs are undesirable in any system with a goal of high availability or Reliability engineering, reliability, be it a business practice, software application, or other industrial system. If there is a SPOF present in a system, it produces a potential interruption to the system that is substantially more disruptive than an error would elsewhere in the system. Overview Systems can be made robust by adding Redundancy (engineering), redundancy in all potential SPOFs. Redundancy can be achieved at various levels. The assessment of a potential SPOF involves identifying the critical components of a complex system that would provoke a total systems failure in case of wikt:malfunction, malfunction. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diskless
A diskless node (or diskless workstation) is a workstation or personal computer without disk drives, which employs network booting to load its operating system from a server. (A computer may also be said to ''act as a diskless node'', if its disks are unused and network booting is used.) Diskless nodes (or computers acting as such) are sometimes known as ''network computers'' or hybrid clients. ''Hybrid client'' may either just mean diskless node, or it may be used in a more particular sense to mean a diskless node which runs ''some'', but not all, applications remotely, as in the thin client computing architecture. Advantages of diskless nodes can include lower production cost, lower running costs, quieter operation, and manageability advantages (for example, centrally managed software installation). In many universities and in some large organizations, PCs are used in a similar configuration, with some or all applications stored remotely but executed locally—again, for manag ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Computer Cluster
A computer cluster is a set of computers that work together so that they can be viewed as a single system. Unlike grid computers, computer clusters have each node set to perform the same task, controlled and scheduled by software. The newest manifestation of cluster computing is cloud computing. The components of a cluster are usually connected to each other through fast local area networks, with each node (computer used as a server) running its own instance of an operating system. In most circumstances, all of the nodes use the same hardware and the same operating system, although in some setups (e.g. using Open Source Cluster Application Resources (OSCAR)), different operating systems can be used on each computer, or different hardware. Clusters are usually deployed to improve performance and availability over that of a single computer, while typically being much more cost-effective than single computers of comparable speed or availability. Computer clusters emerged as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
VMScluster
A VMScluster, originally known as a VAXcluster, is a computer cluster involving a group of computers running the OpenVMS operating system. Whereas tightly coupled multiprocessor systems run a single copy of the operating system, a VMScluster is loosely coupled: each machine runs its own copy of OpenVMS, but the disk storage, lock manager, and security domain are all cluster-wide, providing a single system image abstraction. Machines can join or leave a VMScluster without affecting the rest of the cluster. For enhanced availability, VMSclusters support the use of dual-ported disks connected to two machines or storage controllers simultaneously. Initial release Digital Equipment Corporation (DEC) first announced VAXclusters in May 1983. At that stage, clustering required specialised communications hardware, as well as some major changes to low-level subsystems in the VMS operating system. The software and hardware were designed jointly. VAXcluster support was first added in VAX/VM ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
OpenVMS
OpenVMS, often referred to as just VMS, is a multi-user, multiprocessing and virtual memory-based operating system. It is designed to support time-sharing, batch processing, transaction processing and workstation applications. Customers using OpenVMS include banks and financial services, hospitals and healthcare, telecommunications operators, network information services, and industrial manufacturers. During the 1990s and 2000s, there were approximately half a million VMS systems in operation worldwide. It was first announced by Digital Equipment Corporation (DEC) as VAX/VMS (''Virtual Address eXtension/Virtual Memory System'') alongside the VAX-11/780 minicomputer in 1977. OpenVMS has subsequently been ported to run on DEC Alpha systems, the Itanium-based HPE Integrity Servers, and select x86-64 hardware and hypervisors. Since 2014, OpenVMS is developed and supported by VMS Software Inc. (VSI). OpenVMS offers high availability through computer cluster, clustering—the ability t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
TruCluster
TruCluster is a closed-source high-availability clustering solution for the Tru64 UNIX operating system. It was originally developed by Digital Equipment Corporation (DEC), but was transferred to Compaq in 1998 when Digital was acquired by the company, which then later merged with Hewlett-Packard The Hewlett-Packard Company, commonly shortened to Hewlett-Packard ( ) or HP, was an American multinational information technology company. It was founded by Bill Hewlett and David Packard in 1939 in a one-car garage in Palo Alto, California ... (HP). References TruCluster Software Product Description (SPD) External links High-availability cluster computing {{Compu-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tru64 UNIX
Tru64 UNIX is a discontinued 64-bit UNIX operating system for the DEC Alpha, Alpha instruction set architecture (ISA), currently owned by Hewlett-Packard (HP). Previously, Tru64 UNIX was a product of Compaq, and before that, Digital Equipment Corporation (DEC), where it was known as Digital UNIX (originally DEC OSF/1 AXP). As its original name suggests, Tru64 UNIX is based on the OSF/1 operating system. DEC's previous UNIX product was known as Ultrix and was based on BSD. It is unusual among commercial UNIX implementations, as it is built on top of the Mach kernel developed at Carnegie Mellon University. (Other UNIX and UNIX-like implementations built on top of the Mach kernel are GNU Hurd, NeXTSTEP, MkLinux, and Darwin (operating system), Darwin.) Tru64 UNIX required the SRM firmware, SRM boot firmware found on Alpha-based computer systems. DEC OSF/1 AXP In 1988, Digital Equipment Corporation (DEC) joined with IBM, Hewlett-Packard, and others to form the Open Software Foundat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Open-source License
Open-source licenses are software licenses that allow content to be used, modified, and shared. They facilitate free and open-source software (FOSS) development. Intellectual property (IP) laws restrict the modification and sharing of creative works. Free and open-source licenses use these existing legal structures for an inverse purpose. They Grant (law), grant the recipient the rights to use the software, examine the source code, modify it, and distribute the modifications. These criteria are outlined in the Open Source Definition. After 1980, the United States began to treat software as a literary work covered by copyright law. Richard Stallman founded the free software movement in response to the rise of proprietary software. The term "open source" was used by the Open Source Initiative (OSI), founded by free software developers Bruce Perens and Eric S. Raymond. "Open source" emphasizes the strengths of the Open-source software development, open development model rather tha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cluster Computing
A computer cluster is a set of computers that work together so that they can be viewed as a single system. Unlike Grid computing, grid computers, computer clusters have each Node (networking), node set to perform the same task, controlled and scheduled by software. The newest manifestation of cluster computing is cloud computing. The components of a cluster are usually connected to each other through fast local area networks, with each Node (networking), node (computer used as a server) running its own instance of an operating system. In most circumstances, all of the nodes use the same hardware and the same operating system, although in some setups (e.g. using Open Source Cluster Application Resources (OSCAR)), different operating systems can be used on each computer, or different hardware. Clusters are usually deployed to improve performance and availability over that of a single computer, while typically being much more cost-effective than single computers of comparable s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
