UNICOS

1. UNICOS

2. UNICOS • When it comes to solving real-world problems, leading-edge hardware is only part of the solution. A complete solution also requires a powerful and efficient operating system. Today’s de facto standard for high-performance computing is the UNIX operating system.

3. Following are some of the implementations of UNIX offered by various vendors: • IBM AIX • DEC ULTRIX • SUN SOLARIS • SGI IRIX • CRAY UNICOS

4. Cray Research developed the UNICOS operating system, which is a superset of the UNIX operating system. • UNICOS includes enhancements for parallel scalability, system availability, resource management, and high-bandwidth I/O.

5. UNICOS was designed for highly parallel, multi-user environments. • UNICOS delivers the scalability needed to process large, complex workloads quickly and efficiently.

6. Even though greatly enhanced, UNICOS remains a standard UNIX system, thus it provides a familiar operating environment to the user community.

7. UNICOS provides several advanced utilities to help manage key resources.

8. Utilities include a Unified Resource Manager (URM) that monitors system activity and dynamically adjusts scheduling utilities to manage batch and interactive workloads.

9. UNICOS also provides: • Detailed and sophisticated resource accounting • A user database and quota system • A political scheduler that ensures fair distribution of resources • A Data Migration Facility that monitors disk usage and transfers infrequently used files to offline storage as needed

10. As processor speeds have increased, standard UNIX systems with limits on file size and data transfer rates have been overwhelmed.

11. UNICOS was designed with high I/O bandwidth specifically to avoid the I/O bottlenecks that plague workstation environments.

12. UNICOS I/O scales with the processors in a system and keeps them busy with raw and unbuffered I/O that bypasses standard UNIX system buffering.

13. UNICOS is structured around the kernel, with the system calls acting as the intermediary between the kernel and the commands, operating system features, programming features, and shells.

14. UNICOS users should be familiar with the following UNIX basics: • Man pages • User commands • File system • Jobs and processes • Shells • Environment variables • Text editors

15. Basic User Concepts • Man pages: Online documentation • User commands perform functions such as: • Communication with other users (talk, write) • File manipulation (create, copy, move, remove) • File examination (view, search, compare) • Perform I/O tasks (printing, echoing, reading) • Process control (execution, monitoring, and termination) • Invoke, monitor and control UNICOS features, products and applications

16. Basic User Concepts • UNICOS File System • Regular files • Directory files • Special files • Migrated files (offline files) • Symbolic link files

17. Basic User Concepts • Jobs and Processes • A program is an executable file • A process is an instance of a program in execution • A process is the basic unit of work on UNICOS • The ps command reports process information and allows the user to monitor process status

18. Basic User Concepts • Shells - A shell provides an interface between the user and the kernel. The shell interprets commands and command options entered at the command-line prompt and initiates the appropriate actions in the kernel. • UNICOS supports two shells: • The Korn shell (default) • The C shell

19. Basic User Concepts • Environment variables - The environment is the set of characteristics that determine how you interact with the shell. The UNICOS operating system lets you modify these characteristics with special predefined environment variables. Environment variables usually have a default value if you do not explicitly define them.

20. Basic User Concepts • Editors - Several text editors are available in UNICOS, each of which has its own style, advantages, and disadvantages. Currently available editors are: • Vi • Ed • Emacs