Design and implementation of XML-based Linux file system runner

This thesis presents the design and implementation of XML_based Linux File System Runner (XML_LFS), a file system simulator that integrates the representation ability of Extensible Markup Language (XML) with the beauty of Linux file system architecture. XML_LFS uses a layered approach to design a generic file system runner from scratch utilizing Java programming language and JDOM. The hierarchical directory structure of the file system is kept in an XML file for easy manipulation as well as on disk for crash recovery. UNIX-like file systems such as the Second Extended File System (Ext2), a native mini file system (mini3fs) and Linux kernel codes for file system operations are explored for the real implementation work.;Traditional file system consists of a hierarchical tree, composed of directories and files. Each directory can contain both files and subdirectories. This is an equivalent concept to semi-structured elements in XML. Embedding an XML log file layer into the Linux file system architecture can speed up the directory look up by combining the power of XML and XQuery as well as eliminating the limitations of the existing fixed-attribute file system model by treating files as elements to a customizable XML document. Thus, the whole development environment is more useful for future file system research. The future of XML file system is discussed in detail. Complete system architecture and functionalities are built and the process is described in the thesis. Initial Bonnie-like and Andrew-like benchmarks of the prototype implementation show that XML_LFS achieves the expected performance results

Operating-system support for distributed multimedia

Multimedia applications place new demands upon processors, networks and operating systems. While some network designers, through ATM for example, have considered revolutionary approaches to supporting multimedia, the same cannot be said for operating systems designers. Most work is evolutionary in nature, attempting to identify additional features that can be added to existing systems to support multimedia. Here we describe the Pegasus project's attempt to build an integrated hardware and operating system environment from\ud the ground up specifically targeted towards multimedia

Expert System for UNIX System Reliability and Availability Enhancement

Highly reliable and available systems are critical to the airline industry. However, most off-the-shelf computer operating systems and hardware do not have built-in fault tolerant mechanisms, the UNIX workstation is one example. In this research effort, we have developed a rule-based Expert System (ES) to monitor, command, and control a UNIX workstation system with hot-standby redundancy. The ES on each workstation acts as an on-line system administrator to diagnose, report, correct, and prevent certain types of hardware and software failures. If a primary station is approaching failure, the ES coordinates the switch-over to a hot-standby secondary workstation. The goal is to discover and solve certain fatal problems early enough to prevent complete system failure from occurring and therefore to enhance system reliability and availability. Test results show that the ES can diagnose all targeted faulty scenarios and take desired actions in a consistent manner regardless of the sequence of the faults. The ES can perform designated system administration tasks about ten times faster than an experienced human operator. Compared with a single workstation system, our hot-standby redundancy system downtime is predicted to be reduced by more than 50 percent by using the ES to command and control the system