quiz #3

1.) What are the major activities of OS with regards process management.

OS is responsible for the ff activities in connection with process management.

1. process creation and deletion
2. process suspension and resumption
3. provision of mechanism for:

• process management
• process communication
• deadlock handling (not responding)

2.)What are the major activities of OS with regards main memory.

Some of the activities in connection with memory managemnt that are handled by the OS.

• keep track of w/c parts of the memory are currently beingused and by whom.
• decide with processes to load when memory space becomes available.
• allocate and deallocate memory space as needed

3.)What are the major activities of OS with regards with secondary storage memory.

The OS is responsible for hee ff activities in connection with disk management.

• free space management
• storage allocation
• disk scheduling

4.)What are the major activities of OS with regards with file management.

OS is resposible for the ff activities in connections with file management

• file creation and deletion
• directory creation and deletion
• suppuorts of premitives for manipulating files and directories
• mapping files unto secondary storage
• file back-up on stable (nonvolatile) storage media

5.)What is the purpose of the command interpreter.

Command interpreter serves as the interface between the user and OS

• user friendly mouse based windows environment in the macintosh and in the microsoft windows
• in MS-DOS and UNIX commands are type on the keyboard and displayed on a screen or printing termminal with the enter or return key indicating that a command is complete and ready to be executed.

Many commands are given to the OS by control statements w/c deal w/:

• process creation and management
• i/o handling
• secondary strage management
• main memory management
• file system access
• protection
• networking

VIRTUAL MACHINE

VIRTUAL MACHINE - A virtualvirtualvirtual machinemachinemachine is a type of computer application used to create a virtualvirtualvirtual environment, which is referred to as virtualization. Virtualization allows the user to see the infrastructure of a network through a process of aggregation. Virtualization may also be used to run multiple operating systems at the same time. Through the help of a virtualvirtualvirtual machinemachinemachine, the user can operate software located on the computer platform.

IMPLEMENTETION

"The concept of the virtual machine is one of the most important concepts in computer science today. Emulators use virtual machines, operating systems use virtual machines (Microsoft's .NET), and programming languages use virtual machines (Perl, Java)". Read on for his review of Virtual Machine Design and Implementation in C/C++, an attempt to examine and explain virtual machines and the concepts which allow them to exist.

Top Ten BEnEFITs

1.)Designed for virtual machines running on Windows Server 2008 and Microsoft Hyper-V ServerHyper-V is the next-generation hypervisor-based virtualization platform from Microsoft, which is designed to offer high performance, enhanced security, high availability, scalability, and many other improvements. VMM is designed to take full advantage of these foundational benefits through a powerful yet easy-to-use console that streamlines many of the tasks necessary to manage virtualized infrastructure. Even better, administrators can manage their traditional physical servers right alongside their virtual resources through one unified console.

2.)Support for Microsoft Virtual Server and VMware ESXWith this release, VMM now manages VMware ESX virtualized infrastructure in conjunction with the Virtual Center product. Now administrators running multiple virtualization platforms can rely on one tool to manage virtually everything. With its compatibility with VMware VI3 (through Virtual Center), VMM now supports features such as VMotion and can also provide VMM-specific features like Intelligent Placement to VMware servers.

3.)Performance and Resource Optimization (PRO) Performance and Resource Optimization (PRO) enables the dynamic management of virtual resources though Management Packs that are PRO enabled. Utilizing the deep monitoring capabilities of System Center Operations Manager 2007, PRO enables administrators to establish remedial actions for VMM to execute if poor performance or pending hardware failures are identified in hardware, operating systems, or applications. As an open and extensible platform, PRO encourages partners to design custom management packs that promote compatibility of their products and solutions with PRO’s powerful management capabilities.

4.)Maximize datacenter resources through consolidation A typical physical server in the datacenter operates at only 5 to 15 percent CPU capacity. VMM can assess and then consolidate suitable server workloads onto virtual machine host infrastructure, thus freeing up physical resources for repurposing or hardware retirement. Through physical server consolidation, continued datacenter growth is less constrained by space, electrical, and cooling requirements.

5.)Machine conversions are a snap! Converting a physical machine to a virtual one can be a daunting undertaking—slow, problematic, and typically requiring you to halt the physical server. But thanks to the enhanced P2V conversion in VMM, P2V conversions will become routine. Similarly, VMM also provides a straightforward wizard that can convert VMware virtual machines to VHDs through an easy and speedy Virtual-to-Virtual (V2V) transfer process.

6.)Quick provisioning of new machines In response to new server requests, a truly agile IT department delivers new servers to its business clients anywhere in the network infrastructure with a very quick turnaround. VMM enables this agility by providing IT administrators with the ability to deploy virtual machines in a fraction of the time it would take to deploy a physical server. Through one console, VMM allows administrators to manage and monitor virtual machines and hosts to ensure they are meeting the needs of the corresponding business groups.

7.)Intelligent Placement minimizes virtual machine guesswork in deployment VMM does extensive data analysis on a number of factors before recommending which physical server should host a given virtual workload. This is especially critical when administrators are determining how to place several virtual workloads on the same host machine. With access to historical data—provided by Operations Manager 2007—the Intelligent Placement process is able to factor in past performance characteristics to ensure the best possible match between the virtual machine and its host hardware.

8.)Delegated virtual machine management for Development and Test Virtual infrastructures are commonly used in Test and Development environments, where there is constant provisioning and tear down of virtual machines for testing purposes. This latest version of VMM features a thoroughly reworked and improved self-service Web portal, through which administrators can delegate this provisioning role to authorized users while maintaining precise control over the management of virtual machines.

9.)The library helps keep virtual machine components organized To keep a data center’s virtual house in order, VMM provides a centralized library to store various virtual machine “building blocks”—off-line machines and other virtualization components. With the library’s easy-to-use structured format, IT administrators can quickly find and reuse specific components, thus remaining highly productive and responsive to new server requests and modifications.

10.)Windows PowerShell provides rich management and scripting environment The entire VMM application is built on the command-line and scripting environment, Windows PowerShell. This version of VMM adds additional PowerShell commandlets and “view script” controls, which allow administrators to exploit customizing or automating operations at an unprecedented

EXAMPLE

SYSTEM GENERATION

• System definition: The necessary application and z/TPF system knowledge required to select the hardware configuration and related values used by thez/TPF system software.
  
• ocess of creating the z/TPF system tables and configuration-dependent system software.

• System restart and switchover: The procedures used by the z/TPF system software to ready the configuration for online use.

SYSTEM BOOT

The typical computer system boots over and over again with no problems, starting the computer's operating system (OS) and identifying its hardware and software components that all work together to provide the user with the complete computing experience. But what happens between the time that the user powers up the computer and when the GUI icons appear on the desktop?
In order for a computer to successfully boot, its BIOS, operating system and hardware components must all be working properly; failure of any one of these three elements will likely result in a failed boot sequence.

CHAPTER 3: OPERATING SYSTEM STRUCTURE

system components

• operating system process management -

  – Process: a program in execution

  – Keeps track of each process and it’s state

  – Create, delete, suspend, resume processes; synchronize process communications, handle deadlocks

  – Possibly support threads (executable parts of a process)

• main memory management- Memory is the electronic holding place for instructions and data that the computer's microprocessor can reach quickly. When the computer is in normal operation, its memory usually contains the main parts of the operating system and some or all of the application programs and related data that are being used. Memory is often used as a shorter synonym for random access memory (RAM). This kind of memory is located on one or more microchips that are physically close to the microprocessor in the computer. Most desktop and notebook computers sold today include at least 16 megabytes of RAM, and are upgradeable to include more. The more RAM you have, the less frequently the computer has to access instructions and data from the more slowly accessed hard disk form of storage.

• file management - The term computer file management refers to the manipulation of [document]s and [data] in [Computer file|file]s on a [computer]].Specifically, one may create a new file or edit an existing file and save it; open or load a pre-existing file into memory; or close a file without saving it. Additionally, one may group related files in directories. These tasks are accomplished in different ways in different operating systems and depend on the user interface design and, to some extent, the storage medium being used.

• i/o system management- Input/Output Inc. endured another set of management changes this week, two months after the departures of its top executive.

  But these changes are on the second tier executive level and mark the positioning of the company for participation in the industry's recovery expected next year, say analysts.

  Axel Sigmar will become executive vice president and chief technology officer of I/O. He will also be the president of subsidiary I/O Technologies where he will focus on new generation applications and opportunities for technologies generated within the company.

• secondary amanagement - Secondary storage management is a classical feature of database management systems. It is usually supported through a set of mechanisms. These include index management, data clustering, data buffering, access path selection and query optimization.
  None of these is visible to the user: they are simply performance features. However, they are so critical in terms of performance that their absence will keep the system from performing some tasks (simply because they take too much time). The important point is that they be invisible. The application programmer should not have to write code to maintain indices, to allocate disk storage, or to move data between disk and main memory. Thus, there should be a clear independence between the logical and the physical level of the system.

• protection management-

  – Provide mechanism for controlling access to programs, processes, or users

  – Essential in multitasking and multiuser systems

• command interpreter system - A hardware accelerated I/O data processing engine to execute a minimum number of types of I/O data processing commands in response to a stimulus from a host computer. The data processing engine, referred to as a command interpreter includes a command queue, a logic unit, a multiple purpose interface, at least one memory, and a controlling state machine, that each operate in concert with each other and without software control. The types of commands executed by the command interpreter can include, but are not limited to, an Initialize, Copy, DMA Read, DMA Write, Cumulative Exclusive OR, Verify, Compare, and ECC Check. The execution of commands that specify a source data location and a destination data location are characterized by a plurality of reads to an internal cache from the source data location for each bulk write from the internal cache to the destination data location. The locations of the data operated on by the command interpreter include a local I/O controller memory and a non-local I/O controller memory accessible to the command interpreter by way of an I/O bus.

operating system services

operating system services - Operating systems are responsible for providing essential services within a computer system:
Initial loading of programs and transfer of programs between secondary storage and main memory
Supervision of the input/output devices
File management
Protection facilities

system calls

file managementsystem

• process control
  
  
  Also referred to as simply a file system or filesystem. The system that an operating system or program uses to organize and keep track of files. For example, a hierarchical file system is one that uses directories to organize files into a tree structure.
  Although the operating system provides its own file management system, you can buy separate file management systems. These systems interact smoothly with the operating system but provide more features, such as improved backup procedures and stricter file protection.

• file management -

  – Keeps tracks of available space on the system

  – Maintains directory structure and hierarchy

  – Supports file manipulation commands

  – Keeps track of file information (inode, name, timestamp)

• device management - Device Management is a set of technologies, protocols and standards used to allow the remote management of mobile devices, often involving updates of firmware over the air (FOTA). The network operator, handset OEM or in some cases even the end-user (usually via a web portal) can use Device Management, also known as Mobile Device Management, or MDM, to update the handset firmware/OS, install applications and fix bugs, all over the air. Thus, large numbers of devices can be managed with single commands and the end-user is freed from the requirement to take the phone to a shop or service center to refresh or update.
  For companies, a Device Management system means better control and safety as well as increased efficiency, decreasing the possibility for device downtime. As the number of smart devices increases in many companies today, there is a demand for managing, controlling and updating these devices in an effective way. As mobile devices have become true computers over the years, they also force organizations to manage them properly. Without proper management and security policies, mobile devices pose threat to security: they contain lots of information, while they may easily get into wrong hands. Normally an employee would need to visit the IT / Telecom department in order to do an update on the device. With a Device Management system, that is no longer the issue. Updates can easily be done "over the air". The content on a lost or stolen device can also easily be removed by "wipe" operations. In that way sensitive documents on a lost or a stolen device do not arrive in the hands of others.

• imformation maintenance

  Product information may include all sorts of different data:

• Basic descriptions
• Selling features
• Technical specifications
• Pricing
• Photos
• Logos
• Diagrams
• etc

And each of these may have many variations. Some are used for brochures, some in price lists. Sometimes the same wording is required, sometimes different. One person may be arranging a new brochure, another updating the website. How do you ensure consistency and avoid duplication?

Centralised data maintenance

The answer is to manage all of the data from one place. The data can exist in different forms and even be located in different places but is controlled by one system—infobank.

infobank provides the best of both worlds: distributed data entry with centralised control. Individual users can be dispersed over your network or connected over the Internet.

• simple structure

-->>

• layered approach

-->>Not easy to implement because some functionalities are mutually dependent.

-->>Inefficient because it requires a high number of traversals of interfaces