Addition of Structured Records to the UNIX™ and MS-DOS™ File Systems

A file system consists of operating system code supporting the I/O operations that open, close, create, read and write to files. Record oriented I/O is not a feature of either the UNIX or the MS-DOS native file system. The data is stored by the file system as a sequence of bytes. It is the task of the user to design an application dependent structure on the file system. In the case of logically related fixed or variable length data, a record structure is desirable. This thesis describes a set of extensions to the UNIX and the MS-DOS file systems that supply a record structure to these native file systems. The descriptions of both the UNIX and the MS-DOS native file systems are followed by the extensions to each file system. Program code is provided to demonstrate the MS-DOS extensions

Quantitative analysis of open source projects on SourceForge

Abstrac

Remote boot manager: operating system installer

Dissertação de mestrado em Engenharia Eletrónica Industrial e ComputadoresIn 2018, the number of sold Raspberry Pi computers surpassed the 23 millions , showing the importance of this device in IoT and how it is affecting the world. By connecting each device, is possible to create a cluster, a set of connected computers that works together as a single system, increasing the processing power with a low power consumption. Despite acting like a single system, a cluster involves many devices, which need to be individually rebooted and configured. When done one by one, this tasks consume a lot of time and can be very monotonous. Using TCP/IP and FTP, a remote operating system installer was developed so that it can be remotely controlled by a Central Application. TCP/IP is used for the communication between both endpoints, while FTP is used to transfer the images. The application downloads and installs the operating system commanded by the Central Application while informing about the installation status. As technologies advance, people look for ways to detect errors and malfunctions as quickly as possible because it generates economical losses, and wastes time. Fault tolerance systems come very handy in these situations because they can detect and override these malfunctions. To overcome this problems, it was included in the system a way to reboot the Raspberry Pi in case of malfunctions. Using the Linux Watchdog, is possible to overcome this problem without the usage of external hardware. When a new operating system is installed, it also needs to be monitored, so a daemon was developed so that it can assure that the device can still communicate with the Central Application. The big challenge of this Master Thesis is to join the capability of, monitoring and managing operating systems, communicate and control Raspberry Pi’s and avoid operating systems malfunctions in a single tool, while also making it user friendly and available to everyone who wants to use it.Em 2018, o numero de Raspberry Pi vendidas passou os 23 milhões , mostrando a importância deste dispositivo na IoT e como está a afetar o mundo. Conectando cada dispositivo, é possível criar um cluster, um conjunto de computadores ligados que trabalha como um sistema único, aumentado o poder de processamento com um baixo consumo de energia. Apesar de funcionar como um sistema único, um cluster envolve vários dispositivos, que precisam de ser reiniciados e configurados. Quando feitas uma por uma, estas tarefas consomem muito tempo e podem ser bastante monótonas. Usando TCP/IP e FTP, um instalador de sistemas operativos remoto foi desenvolvido de forma a ser controlado remotamente por uma Aplicação Central. TCP/IP é usado para a comunicação entre os vários pontos, enquanto que FTP é usado para transferir imagens. A aplicação descarrega e instala o sistema operativo comandado pela Aplicação Central ao mesmo tempo que informa acerca do estado da instalação. À medida que a tecnologia avança, as pessoas procuram formas para detetar erros e funcionamentos defeituosos o mais rapidamente possível pois gera perdas económicas, e desperdícios de tempo. Sistemas tolerantes a falhas são bastante convenientes nestas situações pois podem detetar e corrigir esses maus funcionamentos. Para ultrapassar estes problemas, foi incluído no sistema um modo de reiniciar a Raspberry Pi em caso de mau funcionamento. Usando o Linux Watchdog, é possível ultrapassar este problema sem o uso de hardware adicional. Quando um novo sistema operativo é instalado, também é preciso ser monitorizado, portanto um daemon foi desenvolvido para assegurar que o dispositivo consegue ainda comunicar com a Aplicação Central. O grande desafio desta Tese de Mestrado é juntar a capacidade de, monitorizar e gerir sistemas operativos, comunicar e controlar Raspberry Pi’s e evitar maus funcionamentos de sistemas operativos numa única ferramenta, enquanto mantendo amigo do utilizador e acessível para todos os que quiserem usar

Access control in semantic information systems

Access control has evolved in file systems. Early access control was limited and didn't handle identities. Access control then shifted to develop concepts such as identities. The next progression was the ability to take these identities and use lists to control what those identities can do. At this point we start to see more areas implementing access control such as web information systems. Web information systems has themselves started to raise the profile of semantic information. As semantic information systems start to expand new opportunities in access control become available to be explored. This dissertation introduces an experimental file system. The file system explores the concept of utilising metadata in a file system. The metadata is supported through the use of a database system. The introduction of the database enables the use of features such as views within the file system. Databases also provide a rich query language to utilise when nding information. The database aides the development of semantic meaning for the metadata stored. This provides greater meaning to the metadata and enables a platform for rethinking access contro

Linux in Industrial Control Systems

Today the Linux operating system has become a real alternative for industrial control systems. Linux supports all layers in control systems starting with Real-Time or embedded systems for data acquisition, following with treatment, storage, communication and data adaptation, and finally, with supervision and user interfaces. In the last years the Linux development has grown being incorporated in several industrial systems demonstrating high performance, availability and stability for complex processes in chemical, automobile or petrol industries. In many of these industries Linux architectures have been tested and validated successfully. The new CERN policy supporting Linux, as well as the emergence of cheap and robust Linux solutions, motivates its implementation in our safety control and supervision systems in the near future