DOCSLIB.ORG

Einführung in Die Informatik Inf, SAT, Wing, Mi

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Einführung in Die Informatik Inf, SAT, Wing, Mi Einführung in die Informatik Inf, SAT, Wing, Mi Dipl.-Inf., Dipl.-Ing. (FH) Michael Wilhelm Hochschule Harz FB Automatisierung und Informatik [email protected] http://www.miwilhelm.de Raum 2.202 Tel. 03943 / 659 338 FB Automatisierung und Informatik: Einführung in die Informatik 1 Inhalt 1. Grundlagen der Informatik Zahlensysteme, Nachkommazahlen, Single-Format 2. Rechnerarchitekturen (Hard- und Softwaresysteme) Rechnerarchitekturen, Betriebssysteme, 3. Programmierung Sprachen, Datentypen, Datenstrukturen, Programmiermodelle, Compiler, Programmierparadigmen, Domänenspezifische Sprachen, Algorithmen 4. Verteilte Systeme (Netzwerke) 5. Themenfelder der Informatik Datenbanken, Big Data, Multimediaverarbeitung, Software Engineering, KI, Human Computing Interface, Robotics, VR/AR FB Automatisierung und Informatik: Einführung in die Informatik 2 1 Klassifizierung von Rechnerarchitekturen: . Einprozessorsysteme John v. Neumann – Eine CPU – Ein Bus Havard-Rechnerarchitekturen – Mehrere CPU‘s – Mindestens zwei Bussysteme (North- und SouthBridge) – Aufteilen der Geräte in Bezug auf die Geschwindigkeit FB Automatisierung und Informatik: Einführung in die Informatik 3 Von-Neumann Architektur nach John von Neumann Steuerwerk Befehlszähler Befehl Ein-/ Akumulator Speicher Ausgabe Prozessor = Daten Rechenwerk + Arithmetic-Logical-Unit (ALU) + Daten Steuerwerk Speicher ALU Module FB Automatisierung und Informatik: Einführung in die Informatik 4 2 Rechenwerk: ALU MDU BITP SFT ALU: Arithmetisch-Logische-Einheit MDU: Mupliplikation / Division BITP: Bitprozessor SFT: Barrel Shifter (+) Spezialisierte Module (+) Parallele Bearbeitung (+) Optimierte Befehle in Zusammenarbeit mit Compiler (MMX) FB Automatisierung und Informatik: Einführung in die Informatik 5 Arithmetisch-Logische Einheit: X-Register Y-Register ALU: Z-Register Flag-Register FB Automatisierung und Informatik: Einführung in die Informatik 6 3 Arithmetisch-Logische Einheit: Realisierung der Elementaroperationen: ADD, SUB, AND, OR, XOR, NOT, EQ Registerbreite: 8, 16, 32, 64 Ausnahmefälle: Carry: Ergebnis zu groß für Register Z (Überlauf) Overflow: Ergebnis zu groß für die Zahlendarstellung Underflow: Ergebnis zu klein für die Zahlendarstellung Sign: Ergebnis ist negativ Zero: Ergebnis ist null FB Automatisierung und Informatik: Einführung in die Informatik 7 Operationsprinzipien • Der Prozessor (die Central Procesing Unit, CPU) arbeitet taktgesteuert. • Die internen Signale sind binär codiert. • Der Inhalt einer Speicherzelle wird über eine Adresse angesprochen. • Programme und Daten werden sequentiell bearbeitet (single instruction single data, SISD). • Es wird eine feste Wortlänge zur Verarbeitung verwendet. Bitmuster im Speicher repräsentieren 3 Arten: • Daten, Befehle, Adressen FB Automatisierung und Informatik: Einführung in die Informatik 8 4 Die Elemente des Prozessors Das Steuerwerk enthält den Befehlszähler (Adresse des nächsten Befehls), das Befehlsregister und das Adressregister (Adresse des nächsten Datums) Das Rechenwerk (ALU) enthält mehrere Datenregister und Zusatzregister (Flagregister). Die Verknüpfung erfolgt hier gleichzeitig innerhalb eines Takts mit allen Bits je nach Datenbreite Einsatz von Mikrocode zur Steuerung der internen Abläufe: eigener Speicher (ROM), Adressen der Register, Steuerwerk zur Abfolge von Mikrobefehlen in mehreren Takten, Ziel: maximale Parallelisierung bei minimalem Aufwand an Logikschaltungen FB Automatisierung und Informatik: Einführung in die Informatik 9 Modifizierte Architektur •ibib Busse Arbeits- – Adressbus CPU speicher Festplatte – Datenbus – Steuerbus Mikro- prozessor Adressbus Datenbus Steuerbus E/A-Module Zusatz- elektronik Taktgeber FB Automatisierung und Informatik: Einführung in die Informatik 10 5 Motherboard: PCI-BUS Quelle: http://www.hardwaregrundlagen.de) FB Automatisierung und Informatik: Einführung in die Informatik 11 Aufgaben eines Motherboards Die Northbridge sollte die Daten so schnell transportieren können wie sie die CPU liefert. Der Arbeitsspeicher sollte die Daten so schnell aufnehmen können wie sie von der CPU kommen. Die Interne Verbindung (Datenautobahn) zwischen North- und Southbridge sollte so groß sein wie nur möglich, um einen Flaschenhals zu vermeiden. Hier krankt es bei den meisten Mainboards erheblich. Quelle: http://www.hardwaregrundlagen.de) FB Automatisierung und Informatik: Einführung in die Informatik 12 6 Aufbau eines Betriebssystems Anwenderprogramm Kommando-Interpreter BS-Kernel Prozessverwaltung Speicherverwaltung Log. Geräteverwaltung Ein- / Ausgabesysteme Dateisysteme Gerätetreiber Gerätetreiber Schnittstelle zur Hardware CPU / Geräte FB Automatisierung und Informatik: Einführung in die Informatik 13 Kernel- Benutzermodus Dateien,Dateisysteme Werden zur Verwaltung von externen Speicher eingesetzt dienen der dauerhaften Speicherung von Nutzerdaten, Programmen, BS-Daten Speicherung via Laufwerk, Pfad, Dateinamen Umsetzung des logischen Namens in physikalische Parameter Zugriffszeit einer Festplatte ca. 1000.000-fach langsamer als Speicher Speichervolumen ca. 80000-fach größer (Tera-Byte) − Apple: Max Pro: 1,5 TeraByte Hauptspeicher FB Automatisierung und Informatik: Einführung in die Informatik 14 7 Dateien,Dateisysteme Der Hauptspeicher ist schnell und eignet sich hervorragend zur Verwaltung von Daten / Programmen! Probleme: • Hauptspeicher ist begrenzt • Keinen Zugriff auf eigene Daten von anderen Prozessen • Bei Terminierung des Prozesses Datenverlust! FB Automatisierung und Informatik: Einführung in die Informatik 15 Lösung: Die Informationen werden auf einen externen Datenträger Festplatte CD-Laufwerk DVD-Laufwerk Blu-Ray-Laufwerk USB-Laufwerk Bandlaufwerk Netzwerk Cloud-Speicherung gespeichert. FB Automatisierung und Informatik: Einführung in die Informatik 16 8 Aufgaben eines Dateisystems Erzeugen einer Datei, Verzeichnisses Löschen einer Datei Registrierung von Dateien (Windows, chmod Unix) Lesen von Dateien Schreiben in Dateien Schutz der Datei (Rechteverwaltung, UGW=777) Verwaltung der Metainformationen (Attribute) FB Automatisierung und Informatik: Einführung in die Informatik 17 Aufgaben eines Dateisystems (2) Aufbau einer Grundstruktur auf dem Datenträger Partitionierung Formatierung Aufbau einer logischen Reihenfolge (1 bis n) Unabhängigkeit von der phys. Struktur Zylinder, Sektor, Spur sind nur dem Gerät bekannt Aufbauend auf der Blocknumerierung werden Lese- und Schreiboperationen zur Verfügung gestellt Grundstruktur: FAT12, FAT16, FAT32, NTFS, Ext2, Ext3, Ext4, JFS FB Automatisierung und Informatik: Einführung in die Informatik 18 9 FB Automatisierung und Informatik: Einführung in die Informatik 19 Eigenschaften von Dateisysteme: MS-DOS Windows Linux Dateinamen ignore case ignore case case sensitive Verknüpfungen zu Programmen eine pro File eine pro File viele Namenslänge 8.3 255 255 Leerzeichen ja ja nein Filesystem FAT16 FAT32, NTFS ext2, ext3, jfs Link zu Dateien nein nein, ja ja FB Automatisierung und Informatik: Einführung in die Informatik 20 10 Eigenschaften von Dateisysteme: FB Automatisierung und Informatik: Einführung in die Informatik 21 Eigenschaften von Dateien: ASD • Viele moderne Dateisysteme haben das Prinzip der Datei verallgemeinert, so dass man in einer Datei nicht nur eine Folge von Bytes, einen sogenannten Stream (engl. Strom), sondern mehrere solcher Folgen (alternative Datenströme) abspeichern kann FB Automatisierung und Informatik: Einführung in die Informatik 22 11 Microsoft • FAT12/16/32 neuere Variante der FAT-Dateisystemfamilie mit erweiterten Limits gegenüber FAT16, ab Windows 95b bzw. Windows 2000 (wird von neueren Betriebssystemen unterstützt) • exFAT : für den Einsatz auf Flash-Speicher spezialisierte Version von FAT32 • FATX: spezialisierte Variante von FAT16/FAT32 für die Xbox • NTFS (New Technology File System): Journaling-Dateisystem der Windows-NT-Produktlinie, dort das Standarddateisystem. • ReFS (Resilient File System; deutsch Robustes Dateisystem): Neues Dateisystem, eingeführt mit Windows 8[2], basierend auf B+-Bäumen • VFAT (Virtual FAT): Optionale Erweiterung von FAT12/FAT16/FAT32, um Unterstützung für lange Dateinamen und Sonderzeichen zu gewährleisten, ab Windows 95 FB Automatisierung und Informatik: Einführung in die Informatik 23 Apple • Apple DOS : diskettenbasiertes Dateisystem für den Apple II • Apple SOS : Weiterentwicklung von Apple DOS für den Apple III, für Disketten (5,25 ″ und 3,5 ″) und Festplatten (Apple ProFile 5 MB und 10 MB) • Apple ProDOS : Dateisystem der späten Apple-II-Modelle (Apple IIe und Apple IIgs), dateisystemkompatibel mit Apple SOS • MFS (Macintosh File System): hierarchieloses Dateisystem mit Macintosh- spezifischen Eigenschaften, auf frühen Macintosh-Modellen (Macintosh 128 und Macintosh 512) • HFS (Hierarchical File System): hierarchisches Dateisystem mit Macintosh- spezifischen Eigenschaften, auf Macintosh-Modellen ab 1986 (ab Macintosh Plus) • HFS+: weiterentwickelte Variante von HFS mit Journaling und großzügigeren Beschränkungen für Dateigrößen, Volumegrößen usw., Standard unter Mac OS 8.1 bis macOS 10.12 • HFSX : Variante von HFS+ mit Unterscheidung von Groß- und Kleinbuchstaben[1], Standard bis iOS 10.2 • APFS (Apple File System): Nachfolger von HFS+, Standard seit iOS 10.3 und macOS 10.13 (erst mit macOS 10.14 auch auf Fusion Drive) FB Automatisierung und Informatik: Einführung in die Informatik 24 12 Linux • btrfs (Btree File System) – ein sogenanntes Copy-On-Write-Dateisystem • EcryptFS (Enterprise Cryptographic Filesystem) – ein verschlüsselndes
Load more

Recommended publications
  • Copy on Write Based File Systems Performance Analysis and Implementation
    Copy On Write Based File Systems Performance Analysis And Implementation Sakis Kasampalis Kongens Lyngby 2010 IMM-MSC-2010-63 Technical University of Denmark Department Of Informatics Building 321, DK-2800 Kongens Lyngby, Denmark Phone +45 45253351, Fax +45 45882673 [email protected] www.imm.dtu.dk Abstract In this work I am focusing on Copy On Write based file systems. Copy On Write is used on modern file systems for providing (1) metadata and data consistency using transactional semantics, (2) cheap and instant backups using snapshots and clones. This thesis is divided into two main parts. The first part focuses on the design and performance of Copy On Write based file systems. Recent efforts aiming at creating a Copy On Write based file system are ZFS, Btrfs, ext3cow, Hammer, and LLFS. My work focuses only on ZFS and Btrfs, since they support the most advanced features. The main goals of ZFS and Btrfs are to offer a scalable, fault tolerant, and easy to administrate file system. I evaluate the performance and scalability of ZFS and Btrfs. The evaluation includes studying their design and testing their performance and scalability against a set of recommended file system benchmarks. Most computers are already based on multi-core and multiple processor architec- tures. Because of that, the need for using concurrent programming models has increased. Transactions can be very helpful for supporting concurrent program- ming models, which ensure that system updates are consistent. Unfortunately, the majority of operating systems and file systems either do not support trans- actions at all, or they simply do not expose them to the users.
    [Show full text]
  • Membrane: Operating System Support for Restartable File Systems Swaminathan Sundararaman, Sriram Subramanian, Abhishek Rajimwale, Andrea C
    Membrane: Operating System Support for Restartable File Systems Swaminathan Sundararaman, Sriram Subramanian, Abhishek Rajimwale, Andrea C. Arpaci-Dusseau, Remzi H. Arpaci-Dusseau, Michael M. Swift Computer Sciences Department, University of Wisconsin, Madison Abstract and most complex code bases in the kernel. Further, We introduce Membrane, a set of changes to the oper- file systems are still under active development, and new ating system to support restartable file systems. Mem- ones are introduced quite frequently. For example, Linux brane allows an operating system to tolerate a broad has many established file systems, including ext2 [34], class of file system failures and does so while remain- ext3 [35], reiserfs [27], and still there is great interest in ing transparent to running applications; upon failure, the next-generation file systems such as Linux ext4 and btrfs. file system restarts, its state is restored, and pending ap- Thus, file systems are large, complex, and under develop- plication requests are serviced as if no failure had oc- ment, the perfect storm for numerous bugs to arise. curred. Membrane provides transparent recovery through Because of the likely presence of flaws in their imple- a lightweight logging and checkpoint infrastructure, and mentation, it is critical to consider how to recover from includes novel techniques to improve performance and file system crashes as well. Unfortunately, we cannot di- correctness of its fault-anticipation and recovery machin- rectly apply previous work from the device-driver litera- ery. We tested Membrane with ext2, ext3, and VFAT. ture to improving file-system fault recovery. File systems, Through experimentation, we show that Membrane in- unlike device drivers, are extremely stateful, as they man- duces little performance overhead and can tolerate a wide age vast amounts of both in-memory and persistent data; range of file system crashes.
    [Show full text]
  • Filesystems HOWTO Filesystems HOWTO Table of Contents Filesystems HOWTO
    Filesystems HOWTO Filesystems HOWTO Table of Contents Filesystems HOWTO..........................................................................................................................................1 Martin Hinner < [email protected]>, http://martin.hinner.info............................................................1 1. Introduction..........................................................................................................................................1 2. Volumes...............................................................................................................................................1 3. DOS FAT 12/16/32, VFAT.................................................................................................................2 4. High Performance FileSystem (HPFS)................................................................................................2 5. New Technology FileSystem (NTFS).................................................................................................2 6. Extended filesystems (Ext, Ext2, Ext3)...............................................................................................2 7. Macintosh Hierarchical Filesystem − HFS..........................................................................................3 8. ISO 9660 − CD−ROM filesystem.......................................................................................................3 9. Other filesystems.................................................................................................................................3
    [Show full text]
  • A File System Level Snapshot in Ext4
    Computer Engineering and Intelligent Systems www.iiste.org ISSN 2222-1719 (Paper) ISSN 2222-2863 (Online) Vol 2, No.8, 2011 A File System Level Snapshot In Ext4 Uma Nagaraj Computer Engineering Department, Pune University, MAE, Alandi Pune, Maharashtra 412105, India E-mail: [email protected] Ganesh Patil Computer Engineering Department, Pune University, MAE, Alandi Pune, Maharashtra 412105, India E-mail: [email protected] Swapnil Gaikwad Computer Engineering Department, Pune University, MAE, Alandi Pune, Maharashtra 412105, India E-mail: [email protected] Akshay Nehe Computer Engineering Department, Pune University, MAE, Alandi Pune, Maharashtra 412105, India E-mail: [email protected] Ashish Mayekar Computer Engineering Department, Pune University, MAE, Alandi Pune, Maharashtra 412105, India E-mail: [email protected] Received: 2011-10-20 Accepted: 2011-10-29 Published:2011-11-04 Abstract Snapshot makes a copy of current working system. Creating a snapshot with some processing and overheads is important to provide the reliable data service during backup. There are two types of snapshot techniques: volume-based approach and system-based approach. The volume-based Logical Volume Manager provides compact space usability, but requires some space to save snapshot and makes system with extra overheads. The system-based Snapshot works better than volume based. The file system based Snapshot does not need reserve space for snapshot. Therefore, the system-based Snapshot is considered a good solution in the computer environment where large-scale space management capability is not that critical. However, such snapshot feature is available in Linux kernel 2.2, 2.6 in EXT3 file system. In this paper, we proposed a system-based snapshot for the ext4 system in Linux kernel 2.6 or higher.
    [Show full text]
  • VERSIONFS a Versatile and User-Oriented Versioning File System
    VERSIONFS A Versatile and User-Oriented Versioning File System A THESIS PRESENTED BY KIRAN-KUMAR MUNISWAMY-REDDY TO THE GRADUATE SCHOOL IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE IN COMPUTER SCIENCE STONY BROOK UNIVERSITY Technical Report FSL-03-03 December 2003 Abstract of the Thesis Versionfs A Versatile and User-Oriented Versioning File System by Kiran-Kumar Muniswamy-Reddy Master of Science in Computer Science Stony Brook University 2003 File versioning is a useful technique for recording a history of changes. Applications of ver- sioning include backups and disaster recovery, as well as monitoring intruders’ activities. Alas, modern systems do not include an automatic and easy-to-use file versioning system. Existing backup systems are slow and inflexible for users. Even worse, they often lack backups for the most recent day’s activities. Online disk snapshotting systems offer more fine-grained versioning, but still do not record the most recent changes to files. Moreover, existing systems also do not give individual users the flexibility to control versioning policies. We designed a lightweight user-oriented versioning file system called Versionfs. Versionfs works with any file system, whether local or remote, and provides a host of user-configurable policies: versioning by users, groups, processes, or file names and extensions; version retention policies by maximum number of versions kept, age, or total space consumed by versions of a file; version storage policies using full copies, compressed copies, or deltas. Versionfs creates file versions automatically, transparently, and in a file-system portable manner—while maintaining Unix semantics. A set of user-level utilities allow administrators to configure and enforce default policies; users are able to set policies within configured boundaries, as well as view, control, and recover files and their versions.
    [Show full text]
  • The Third Extended File System with Copy-On-Write
    Limiting Liability in a Federally Compliant File System Zachary N. J. Peterson The Johns Hopkins University Hopkins Storage Systems Lab, Department of Computer Science Regulatory Requirements z Data Maintenance Acts & Regulations – HIPAA, GISRA, SOX, GLB – 4,000+ State and Federal Laws and Regulations with regards to storage z Audit Trail – creating a “chain of trust” – Files are versioned over time – Authenticated block sharing (copy-on-write) between versions. z Disk Encryption – Privacy and Confidentiality – Non-repudiation Hopkins Storage Systems Lab, Department of Computer Science Secure Deletion in a Regulatory Environment z Desire to limit liability when audited – Records that go out of audit scope do so forever – When a disk is subpoenaed old or irrelevant data are inaccessible z Existing Techniques – Secure overwrite [Gutmann] – File key disposal in disk encrypted systems [Boneh & Lipton] z Existing solutions don’t work well in block- versioning file systems Hopkins Storage Systems Lab, Department of Computer Science Technical Problems z Secure overwriting of noncontiguous data blocks is slow and inefficient – When versions share blocks, data to be overwritten may be noncontiguous z Cannot dispose file keys in a versioning file system – Blocks encrypted with a particular key need to be available in future versions z User space tools are inadequate – Can’t delete metadata – Can’t be interposed between file operations – Truncate may leak data – Difficult to be synchronous Hopkins Storage Systems Lab, Department of Computer Science
    [Show full text]
  • A Secure Context-Sensitive File System Britton Dennis, Tyler Travis
    A Secure Context-Sensitive File System determined within a split second. Computers, like humans, experience a variety of contexts Britton Dennis, Tyler Travis, Clark Wood at different times. The difference between visiting the real Facebook website and a clever Abstract imposter may be the difference between seeing HTTP and HTTPS in one’s browser. In this paper we present a secure, Until now, security context was determined in context-sensitive file system. Our system was real-time by users picking up various context designed to offer block level security as well as clues and modifying their own behavior present access to a file under multiple, accordingly. The disadvantage of this manual, constantly shifting contexts in diverse fashions. case-by-case decision is that humans make Some of our related works illustrate different mistakes. A less technologically-savvy person ways to use the different context / view may not even notice that what appears to be approach, but these prior works raise similar their banking website has an invalid SSL security concerns, and consequently we chose certificate, and because additional security to design our file system to limit the information comes at the cost of usability, users often that gets presented to the viewer. This is ignore such warnings, even if they know what because of a fundamental capacity for the warning means. The burden of determining sensitive data leakage in these systems, owing the secureness of a given system cannot be to the presence of naming collisions. This placed solely upon end-users. becomes important when trying to design a In order to mitigate these concerns, secure file system which adheres to such researchers are developing context-aware security schemes as Biba or BLP[3, 2], which software.
    [Show full text]
  • Provenance-Based Computing
    UCAM-CL-TR-930 Technical Report ISSN 1476-2986 Number 930 Computer Laboratory Provenance-based computing Lucian Carata December 2018 15 JJ Thomson Avenue Cambridge CB3 0FD United Kingdom phone +44 1223 763500 https://www.cl.cam.ac.uk/ c 2018 Lucian Carata This technical report is based on a dissertation submitted July 2016 by the author for the degree of Doctor of Philosophy to the University of Cambridge, Wolfson College. Technical reports published by the University of Cambridge Computer Laboratory are freely available via the Internet: https://www.cl.cam.ac.uk/techreports/ ISSN 1476-2986 Provenance-based computing Lucian Carata Summary Relying on computing systems that become increasingly complex is difficult: with many factors potentially affecting the result of a computation or its properties, understanding where problems appear and fixing them is a challenging proposition. Typically, the process of finding solutions is driven by trial and error or by experience-based insights. In this dissertation, I examine the idea of using provenance metadata (the set of elements that have contributed to the existence of a piece of data, together with their relationships) instead. I show that considering provenance a primitive of computation enables the ex- ploration of system behaviour, targeting both retrospective analysis (root cause analysis, performance tuning) and hypothetical scenarios (what-if questions). In this context, prove- nance can be used as part of feedback loops, with a double purpose: building software that is able to adapt for meeting certain quality and performance targets (semi-automated tun- ing) and enabling human operators to exert high-level runtime control with limited previous knowledge of a system’s internal architecture.
    [Show full text]
  • Membrane: Operating System Support for Restartable File Systems
    Membrane: Operating System Support for Restartable File Systems SWAMINATHAN SUNDARARAMAN, SRIRAM SUBRAMANIAN, ABHISHEK RAJIMWALE, ANDREA C. ARPACI-DUSSEAU, REMZI H. ARPACI-DUSSEAU, and MICHAEL M. SWIFT University of Wisconsin-Madison We introduce Membrane, a set of changes to the operating system to support restartable file systems. Membrane allows an operating system to tolerate a broad class of file system failures, and does so while remaining transparent to running applications; upon failure, the file system restarts, its state is restored, and pending application requests are serviced as if no failure had occurred. Membrane provides transparent recovery through a lightweight logging and checkpoint infrastructure, and includes novel techniques to improve performance and correctness of its fault- 11 anticipation and recovery machinery. We tested Membrane with ext2, ext3, and VFAT. Through experimentation, we show that Membrane induces little performance overhead and can tolerate a wide range of file system crashes. More critically, Membrane does so with little or no change to existing file systems, thus improving robustness to crashes without mandating intrusive changes to existing file-system code. Categories and Subject Descriptors: D.4.5 [Operating Systems]: Reliability—Fault-tolerance General Terms: Design, Algorithms, Reliability Additional Key Words and Phrases: Checkpointing, restartability, fault recovery, file systems ACM Reference Format: Sundararaman, S., Subramanian, S., Rajimwale, A., Arpaci-Dusseau, A. C., Arpaci-Dusseau, R. H., and Swift, M. M. 2010. Membrane: Operating System Support for Restartable File Systems. ACM Trans. Storage 6, 3, Article 11 (September 2010), 30 pages. DOI = 10.1145/1837915.1837919 http://doi.acm.org/10.1145/1837915.1837919 An earlier version of this paper appeared in the Proceedings of the 8th File and Storage Technologies Conference (FAST).
    [Show full text]
  • 3 Comandos Linux
    Livro Eletrônico Aula 00 Sistemas Operacionais p/ AL-BA (Analista Legislativo - TI) Pós-Edital Professor: Celson Carlos Martins Junior Aula Demonstrativa Celson Carlos Martins Junior Aula 00 ESCLARECIMENTOS INICIAIS .......................................................................................................................................... 3 1 – INTRODUÇÃO .............................................................................................................................................................. 5 1.1 COMMUNITY ENTERPRISE OPERATING SYSTEM ........................................................................................... 6 1.2 RED HAT ENTERPRISE LINUX ......................................................................................................................... 8 1.3 INSTALAÇÃO CENTOS ................................................................................................................................... 10 1.4 GERENCIADOR INICIALIZAÇÃO .................................................................................................................... 17 1.5 SISTEMAS DE ARQUIVOS ................................................................................................................................ 18 1.6 SISTEMAS RAID ............................................................................................................................................. 20 1.7 RESOLUÇÃO DE QUESTÕES ..........................................................................................................................
    [Show full text]
  • Ort Seite 127.0.0.1 --> Loopback 1-To-1 Relation (Relational Database)
    1 2 3 <== Hierarchie Ort Seite # 127.0.0.1 --> loopback 1-to-1 relation (relational database) C7 - Databases 63 1-to-n relation (relational database) C7 - Databases 62 255.255.255.255 --> broadcast address: IPv4, DHCPv4 ff02::1:2 --> broadcast address: DHCPv6 ff:ff:ff:ff:ff:ff --> broadcast address: MAC A abortable locks C4 - Locks 65-67 abortable MCS lock C4 - Locks 67 absorbing states (Markov chains) C11 - Markov Chains & PageRank 97 abstraction (device driver) C9 - I/O Devices / File Systems 7 access method (file system) C9 - I/O Devices / File Systems 62 ACK (acknowledgement) packet C2 - Transport Layer (L3) 23 acknowledgement packet --> ACK additive increase / multiplicative decrease --> AIMD address --> broadcast address --> IPv4 / IPv6 --> MAC address block --> IPv4 address prefix --> IPv4 address resolution protocol --> ARP adjacency list --> graphs AIMD (additive increase / multiplicative decrease) C2 - Transport Layer (L3) 21 allocation structure (vsfs) C9 - I/O Devices / File Systems 63 ALock (Anderson queue lock) --> locks AM (amplitude modulation) --> modulation amplitude modulation (AM) --> modulation anchor text C11 - Markov Chains & PageRank 102 Anderson queue lock (ALock) --> locks anonymous pipe --> (ordinary) pipe aperiodic (Markov chains) C11 - Markov Chains & PageRank 99 distinguish aperiodic states and an aperiodic Markov chain! ARP (address resolution protocol) C10 - Link Layer (L1) 79 arrival probability (Markov chains) C11 - Markov Chains & PageRank 95 AS (autonomous system) C1 - Network Layer (L2) 8 ASN (autonomous
    [Show full text]
  • Abkürzungs-Liste ABKLEX
    Abkürzungs-Liste ABKLEX (Informatik, Telekommunikation) W. Alex 1. Juli 2021 Karlsruhe Copyright W. Alex, Karlsruhe, 1994 – 2018. Die Liste darf unentgeltlich benutzt und weitergegeben werden. The list may be used or copied free of any charge. Original Point of Distribution: http://www.abklex.de/abklex/ An authorized Czechian version is published on: http://www.sochorek.cz/archiv/slovniky/abklex.htm Author’s Email address: [email protected] 2 Kapitel 1 Abkürzungen Gehen wir von 30 Zeichen aus, aus denen Abkürzungen gebildet werden, und nehmen wir eine größte Länge von 5 Zeichen an, so lassen sich 25.137.930 verschiedene Abkür- zungen bilden (Kombinationen mit Wiederholung und Berücksichtigung der Reihenfol- ge). Es folgt eine Auswahl von rund 16000 Abkürzungen aus den Bereichen Informatik und Telekommunikation. Die Abkürzungen werden hier durchgehend groß geschrieben, Akzente, Bindestriche und dergleichen wurden weggelassen. Einige Abkürzungen sind geschützte Namen; diese sind nicht gekennzeichnet. Die Liste beschreibt nur den Ge- brauch, sie legt nicht eine Definition fest. 100GE 100 GBit/s Ethernet 16CIF 16 times Common Intermediate Format (Picture Format) 16QAM 16-state Quadrature Amplitude Modulation 1GFC 1 Gigabaud Fiber Channel (2, 4, 8, 10, 20GFC) 1GL 1st Generation Language (Maschinencode) 1TBS One True Brace Style (C) 1TR6 (ISDN-Protokoll D-Kanal, national) 247 24/7: 24 hours per day, 7 days per week 2D 2-dimensional 2FA Zwei-Faktor-Authentifizierung 2GL 2nd Generation Language (Assembler) 2L8 Too Late (Slang) 2MS Strukturierte
    [Show full text]