Dissertations / Theses on the topic 'UNIX System V (Computer operating system)'

Tuning a computer system effectively requires prior studies on the performance of the system. There are different types of tools available to measure a system: hardware, firmware and software. This thesis presents the design and implementation of an event monitor, which is one type of software tools. The event monitor was developed on a SUN1 workstation running UNIX 4.2bsd version 1.4. Six types of events were selected to be measured, namely transactions, logins/logouts, pageins, pageouts, disk I/Os and forks/exits. The operating system was modified to include probes to trap these events. For a final testing of the event monitor, it was ported and installed onto a SUN3 workstation running UNIX 4.2bsd version 3.2. Measurements collected were analyzed by a capacity planning package condenser. The results give an indication of the system workload and the system performance. Benchmarks were also set up to measure the overhead incurred by the event monitor.
Science, Faculty of
Computer Science, Department of
Graduate

A command language interpreter (CLI) translates commands entered by the user into system actions. The shell is a specific type of CLI that was originally designed and used with UNIX operating systems.The author proposes to design and implement a shell-like CLI on top of the VMS operating system. The shell will enhance VMS features by providing an easier to use syntax and by providing features that are not currently available through VMS. These features include piping facilities and the ability to enter and/or reference multiple commands from a single command line. A language reference manual is provided with the J-shell. This manual explains the features and commands of the J-shell.

International Telemetering Conference Proceedings / November 04-07, 1991 / Riviera Hotel and Convention Center, Las Vegas, Nevada
In this paper we describe the design of the REAL/STAR 2000 system, a highperformance real-time computer for telemetry applications. The REAL/STAR 2000 is a symmetric, tightly-coupled multiprocessor, optimized for real-time processing. The system provides a high level of scalability and flexibility by supporting three configurations: single, dual, and quad processor configurations, based on Motorola 88100 RISC processors. The system runs the multiprocessor REAL/IX operating system, a real-time implementation of the AT&T UNIX System V. It compiles with BCS and OCS standards, meets the POSIX 1003.1 standard, and has the current functionality of the emerging POSIX 1003.4 real-time standard. The REAL/STAR 2000 promotes an open system approach to real-time computing by supporting major industry standards. Benchmark results are also presented in the paper.

The U.S. Navy transitioned to Computer-Based Training (CBT) in A and C schools in 2003 after a 2001 Revolution in Training report claimed that the Navy would realize savings in cost and training time without negatively affecting the quality of sailors arriving to the Fleet. This thesis analyzes Operating and Support (O and S) cost data for the AN/SQQ-89(v) sonar system to determine whether the transition to CBT contributed to increased Fleet maintenance costs. Determining how actions to change one aspect of a system affects other areas of the system will provide insight for future decisions affecting O and S cost, system life cycles, and Fleet material readiness.

This master's thesis deals with Linux kernel security from the attacker's point of view. It maps methods and techniques of disguising the computing resources used by today's IT pirates. The thesis presents a unique method of attack directed on the system call interface and implemented in the form of two tools (rootkits). The thesis consists of a theoretical and a practical part. Emphasis is placed especially on the practical part, which manifests the presented information in the form of experiments and shows its use in real life. Readers are systematically guided as far as the creation of a unique rootkit, which is capable of infiltrating the Linux kernel by a newly discovered method -- even without support of loadable modules. A part of the thesis focuses on the issue of detecting the discussed attacks and on effective defence against them.

Many embedded systems lack a memory management unit (MMU) and thus often also lack protection of memory. This causes these systems to be less robust since the operating system (OS), processes, and threads are no longer isolated from each other. This is also a potential security issue and with the number of embedded systems rapidly increasing as a result of the rise of Internet of things (IoT), vulnerabilities like this could become a major problem. However, with a recent update to the RISC-V processor architecture, a possibility to isolate regions of memory without an MMU was introduced. This study aims to identify problems and possibilities of implementing such memory protection with RISC-V. Based on a study of literature and documentation on memory protection and the RISC-V architecture, a prototype was designed and implemented to determine potential problems and evaluate performance in terms of execution time and memory cost. The developed prototype showed aworking implementation of memory protection for the memory regions with RISC-V. The evaluation of the prototype demonstrated an increase in context switch execution time and memory usage. The results indicate that the implemented memory protection comes with an increased cost in performance with a constant factor and a small memory overhead. Therefore, it is recommended that implementations that wish to implement memory protection with RISC-V on smaller embedded systems where time and memory may be crucial takes the overhead in consideration. Further research and testing is needed to identify optimizations that could improve the performance as well as discover security flaws.
Många inbyggda system saknar en enhet för minneshantering (s.k. MMU) och saknar därför oftast minnesskydd. Detta leder till att dessa system blir mindre robusta eftersom operativsystemet, processer och trådar inte längre är isolerade från varandra. Detta är också en säkerhetsbrist och med antalet inbyggda system som snabbt ökar på grund av tillväxten av Internet of things (IoT), så kan sårbarheter som denna bli ett stort problem. Med en nyligen introducerad uppdatering av RISC-Vprocessor arkitekturen, så introducerades en möjlighet till att isolera minne utan hjälp av en MMU. Denna studie syftar till att identifiera problem och möjligheter av att implementera sådant minneskydd med RISC-V. Baserat på en studie av litteratur och dokumentation om minnesskydd och RISC-V arkitekturen designades och implementerades en prototyp för att hjälpa till att fastställa problem och möjligheter samt göra en utvärdering med avseende på prestanda- och minneskostnader. Den utvecklade prototypen visade en fungerande implementering av minneskydd för minnesregioner med RISC-V. Utvärderingen av prototypen visade en ökad exekveringstid för kontextbyten och ökad minnesanvändning. Resultaten indikerar att det implementerade minneskyddet kommer med en ökad kostnad i prestanda med en konstant faktor och en liten omkostnad i minne. Därför rekommenderas att implementeringar som vill implementera minneskydd med RISC-V på mindre inbyggda system där tid och minne kan vara avgörande tar hänsyn till omkostnaderna. Ytterligare studier och tester behövs för att identifiera optimeringar som kan förbättra prestandan och upptäcka säkerhetsbrister.

Il lavoro è stato suddiviso in tre macro-aree. Una prima riguardante un'analisi teorica di come funzionano le intrusioni, di quali software vengono utilizzati per compierle, e di come proteggersi (usando i dispositivi che in termine generico si possono riconoscere come i firewall). Una seconda macro-area che analizza un'intrusione avvenuta dall'esterno verso dei server sensibili di una rete LAN. Questa analisi viene condotta sui file catturati dalle due interfacce di rete configurate in modalità promiscua su una sonda presente nella LAN. Le interfacce sono due per potersi interfacciare a due segmenti di LAN aventi due maschere di sotto-rete differenti. L'attacco viene analizzato mediante vari software. Si può infatti definire una terza parte del lavoro, la parte dove vengono analizzati i file catturati dalle due interfacce con i software che prima si occupano di analizzare i dati di contenuto completo, come Wireshark, poi dei software che si occupano di analizzare i dati di sessione che sono stati trattati con Argus, e infine i dati di tipo statistico che sono stati trattati con Ntop. Il penultimo capitolo, quello prima delle conclusioni, invece tratta l'installazione di Nagios, e la sua configurazione per il monitoraggio attraverso plugin dello spazio di disco rimanente su una macchina agent remota, e sui servizi MySql e DNS. Ovviamente Nagios può essere configurato per monitorare ogni tipo di servizio offerto sulla rete.

The theme of this diploma thesis is operating system OS X Server services by Apple. The thesis presents the possibility of their use for data sharing and communication among users of computer networks and examines the practical use of the information society. The opening chapter is an introduction of OS X Server. The second chapter deals with the progression of the system, its features, hardware selection, system requirements, support and overall evaluation. The third chapter is devoted to server services and their protocols. The fourth chapter presents the basic tools needed for server management and data protection. The essence of the work consists of the practical part, which provides services server uses based on the case study of a musical recording studio 3bees. Part of this thesis is also Research of the OS X Server deployment in the Czech Republic, which was organised by questionnaire survey. The survey focuses on the analysis of the environment and conditions in which the product is deployed and the most frequently used services.