Jailbreaking refers to privilege escalation on an Apple device to remove software restrictions imposed by Apple on iOS, iPadOS, tvOS, watchOS, bridgeOS and audioOSoperating systems. Typically it is done through a series of kernel patches. A jailbroken device permits root access within the operating system and provides the opportunity to install software not available through the iOS App Store. Different devices and versions are exploited with a variety of tools. Apple views jailbreaking as a violation of the End-user license agreement, and strongly cautions device owners from attempting to achieve root access through exploitation of vulnerabilities.
Xsan
Xsan (/ˈɛksæn/) is Apple Inc.'s storage area network (SAN) or clustered file system for macOS. Xsan enables multiple Mac desktop and Xserve systems to access shared block storage over a Fibre Channel network. With the Xsan file system installed, these computers can read and write to the same storage volume at the same time. Xsan is a complete SAN solution that includes the metadata controller software, the file system client software, and integrated setup, management and monitoring tools.
Xsan has all the normal features to be expected in an enterprise shared disk file system, including support for large files and file systems, multiple mounted file systems, metadata controller failover for fault tolerance, and support for multiple operating systems.
Open Source
Open source is a source code that is made freely available for possible modification and redistribution. Products include permission to use the source code, design documents, or content of the product. It most commonly refers to the open-source model, in which open-source software or other products are released under an open-source license as part of the open-source-software movement. Use of the term originated with software, but has expanded beyond the software sector to cover other open content and forms of open collaboration.
The term "open source", as used to describe software, was first proposed by a group of people in the free software movement who were critical of the political agenda and moral philosophy implied in the term "free software" and sought to reframe the discourse to reflect a more commercially minded position. Moreover, the ambiguity of the term "free software" was seen as discouraging business adoption. The group included Christine Peterson, Todd Anderson, Larry Augustin, Jon Hall, Sam Ockman, Michael Tiemann and Eric S. Raymond. Peterson suggested "open source" at a meeting held at Palo Alto, California, in reaction to Netscape's announcement in January 1998 of a source code release for Navigator. Linus Torvalds gave his support the following day, and Phil Hughes backed the term in Linux Journal. Richard Stallman, the founder of the free software movement, initially seemed to adopt the term, but later changed his mind. Netscape released its source code under the Netscape Public License and later under the Mozilla Public License.
Pareto Principle
The Pareto principle states that for many outcomes roughly 80% of consequences come from 20% of the causes (the “vital few”).[1]Other names for this principle are the 80/20 rule, the law of the vital few, or the principle of factor sparsity.
…The term 80/20 is only a shorthand for the general principle at work. In individual cases, the distribution could just as well be, say, nearer to 90/10 or 70/30. There is no need for the two numbers to add up to the number 100, as they are measures of different things, (e.g., 'number of customers' vs 'amount spent').
cloud
“Cloud” is a nebulous term. -rws
dark fibre
A dark fibre or unlit fibre is an unused optical fibre, available for use in fibre-optic communication. Dark fibre originally referred to the potential network capacity of telecommunication infrastructure. Dark fibre may be leased from a network service provider.
…During the dot-com bubble, a large number of telephone companies built optical-fibre networks, each with the business plan of cornering the market in telecommunications by providing a network with sufficient capacity to take all existing and forecast traffic for the entire region served. This was based on the assumption that telecoms traffic, particularly data traffic, would continue to grow exponentially for the foreseeable future. The advent of wavelength-division multiplexing reduced the demand for fibre by increasing the capacity of a single fibre by a factor of as much as 100. According to Gerry Butters, the former head of Lucent's Optical Networking Group at Bell Labs, the amount of data that could be carried by an optical fibre was doubling every nine months at the time. This progress in the ability to carry data over fibre reduced the need for more fibres. As a result, the wholesale price for data communications collapsed and a number of these companies filed for bankruptcy protection as a result. Global Crossing and Worldcom are two high-profile examples in the United States.
Similar to the Railway Mania, the misfortune of one market sector became the good fortune of another, and this overcapacity created a new telecommunications sector.
