Memory pagingIn computer operating systems, memory paging (or swapping on some Unix-like systems) is a memory management scheme by which a computer stores and retrieves data from secondary storage for use in main memory. In this scheme, the operating system retrieves data from secondary storage in same-size blocks called pages. Paging is an important part of virtual memory implementations in modern operating systems, using secondary storage to let programs exceed the size of available physical memory.
Supervisor Call instructionThis article covers the specific instruction on the IBM System/360 and successor mainframe computers, and compatible machines. For the general concept of an instruction for issuing calls to an operating system, see System call. A Supervisor Call instruction (SVC) is a hardware instruction used by the System/360 family of IBM mainframe computers up to contemporary zSeries, the Amdahl 470V/5, 470V/6, 470V/7, 470V/8, 580, 5880, 5990M, and 5990A, and others; Univac 90/60, 90/70 and 90/80, and possibly others; the Fujitsu M180 (UP) and M200 (MP), and others; and is also used in the Hercules open source mainframe emulation software.
Cloud computingCloud computing is the on-demand availability of computer system resources, especially data storage (cloud 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.
Rate-monotonic schedulingIn computer science, rate-monotonic scheduling (RMS) is a priority assignment algorithm used in real-time operating systems (RTOS) with a static-priority scheduling class. The static priorities are assigned according to the cycle duration of the job, so a shorter cycle duration results in a higher job priority. These operating systems are generally preemptive and have deterministic guarantees with regard to response times. Rate monotonic analysis is used in conjunction with those systems to provide scheduling guarantees for a particular application.
SecuritySecurity is protection from, or resilience against, potential harm (or other unwanted coercion) caused by others, by restraining the freedom of others to act. Beneficiaries (technically referents) of security may be of persons and social groups, objects and institutions, ecosystems or any other entity or phenomenon vulnerable to unwanted change. Security mostly refers to protection from hostile forces, but it has a wide range of other senses: for example, as the absence of harm (e.g.
Linux MintLinux Mint is a community-driven Linux distribution based on Ubuntu (which is in turn based on Debian), bundled with a variety of free and open-source applications. It can provide full out-of-the-box multimedia support for those who choose to include proprietary software such as multimedia codecs. Compared to Ubuntu, it uses a different Cinnamon interface by default, using a different, more traditional layout that can be customized by dragging the applets and creating panels. New applets can also be downloaded.
Kexeckexec, abbreviated from kernel execute and analogous to the Unix/Linux kernel call exec, is a mechanism of the Linux kernel that allows booting of a new kernel from the currently running one. Essentially, kexec skips the bootloader stage and hardware initialization phase performed by the system firmware (BIOS or UEFI), and directly loads the new kernel into main memory and starts executing it immediately. This avoids the long times associated with a full reboot, and can help systems to meet high-availability requirements by minimizing downtime.
Cloud computing securityCloud computing security or, more simply, cloud security, refers to a broad set of policies, technologies, applications, and controls utilized to protect virtualized IP, data, applications, services, and the associated infrastructure of cloud computing. It is a sub-domain of computer security, network security, and, more broadly, information security. Cloud computing and storage provide users with the capabilities to store and process their data in third-party data centers.
National securityNational security, or national defence, is the security and defence of a sovereign state, including its citizens, economy, and institutions, which is regarded as a duty of government. Originally conceived as protection against military attack, national security is widely understood to include also non-military dimensions, such as the security from terrorism, minimization of crime, economic security, energy security, environmental security, food security, and cyber-security.
Earliest deadline first schedulingEarliest deadline first (EDF) or least time to go is a dynamic priority scheduling algorithm used in real-time operating systems to place processes in a priority queue. Whenever a scheduling event occurs (task finishes, new task released, etc.) the queue will be searched for the process closest to its deadline. This process is the next to be scheduled for execution.
OS/2OS/2 (Operating System/2) is a series of computer operating systems, initially created by Microsoft and IBM under the leadership of IBM software designer Ed Iacobucci. As a result of a feud between the two companies over how to position OS/2 relative to Microsoft's new Windows 3.1 operating environment, the two companies severed the relationship in 1992 and OS/2 development fell to IBM exclusively. The name stands for "Operating System/2", because it was introduced as part of the same generation change release as IBM's "Personal System/2 (PS/2)" line of second-generation personal computers.
Security guardA security guard (also known as a security inspector, security officer, factory guard, or protective agent) is a person employed by a government or private party to protect the employing party's assets (property, people, equipment, money, etc.) from a variety of hazards (such as crime, waste, damages, unsafe worker behavior, etc.) by enforcing preventative measures.
