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Unit - 6

Inter-Process Communication (IPC):

Inter-Process Communication (IPC) refers to the mechanisms and techniques used by processes to communicate and share data with each other. There are several methods for IPC in UNIX/Linux systems:

  1. Process Tracing: Process tracing is the ability to monitor and trace the execution of processes. Tools like strace and ptrace allow you to monitor system calls, signals, and other events of a running process, helping in debugging and understanding the behavior of processes.

  2. System V IPC: System V IPC provides a set of mechanisms for IPC, including:

    a. Shared Memory: Processes can share a common memory segment to exchange data efficiently. This shared memory is created using system calls like shmget, shmat, and shmdt.

    b. Message Queues: Processes can communicate by sending and receiving messages through message queues. System calls such as msgget, msgsnd, and msgrcv are used to create, send, and receive messages.

    c. Semaphores: Semaphores are used for synchronization and mutual exclusion between processes. They are created and manipulated using system calls like semget, semop, and semctl.

  3. Network Communication and Sockets: Network communication enables processes running on different systems to communicate with each other. Sockets are the primary mechanism for network communication in UNIX/Linux. Processes can create network sockets (IPv4 or IPv6) using system calls like socket, and then use functions like bind, listen, connect, send, and receive to establish connections and exchange data over the network.

Managing the System and Network Connections in Linux:

Managing the system and network connections in Linux involves various tasks, including:

  1. Monitoring Resources: Linux provides tools like top, htop, and sar to monitor system resources such as CPU usage, memory utilization, disk I/O, and network activity. These tools help in identifying performance bottlenecks and optimizing system resources.

  2. Mastering Time: The date command allows you to view and modify the system date and time. Additionally, tools like timedatectl and ntpd help in managing time synchronization with network time servers.

  3. Managing the Boot Process: The boot process in Linux is managed by the bootloader (e.g., GRUB) and the init system (e.g., systemd). Configurations related to the boot process, such as kernel parameters, startup services, and runlevels, are managed using configuration files like /etc/default/grub and /etc/systemd/.

  4. Controlling Startup and Run Levels: The systemctl command is used to control and manage services in Linux. It allows you to start, stop, enable, disable, and check the status of services. The chkconfig command is used to configure services to start automatically at specific run levels.

  5. Configuring Networks from the GUI: Linux distributions provide graphical user interfaces (GUIs) such as NetworkManager or GNOME Control Center to configure network settings. These GUI tools allow users to set up wired or wireless connections, configure IP addresses, DNS settings, and manage network profiles.

  6. Managing Network Interface Cards: Network interface cards (NICs) can be managed using commands like ifconfig or ip. These commands allow you to view and configure network interfaces, set IP addresses, enable or disable interfaces, and manage network routing.

  7. Connections: Using Wireless Connections: Linux supports wireless networking and provides tools like iwconfig and nmcli to manage wireless connections. These tools allow you to scan for available wireless networks, connect to a specific network, and configure wireless settings.

  8. Troubleshooting Network Problems: When troubleshooting network problems in Linux, tools like ping, traceroute, netstat, and tcpdump are commonly used. These tools help in diagnosing connectivity issues, checking network configurations, and capturing network packets for analysis.

Effective management of system and network connections in Linux requires a good understanding of the available tools and configurations, as well as knowledge of networking concepts and protocols.

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Contributions

List a few examples of the ways you are active in the cloud native community. (GitHub, Meetup you have organized or spoken at, etc.) Please be as specific as possible.

Jan 2, 2024
Unit - 1

Unix System Structure: The Unix operating system follows a hierarchical file system structure. At the top level is the root directory ("/"), which serves as the starting point for all file paths. The file system is organized into directories, which can contain files and subdirectories. Each file and directory is uniquely identified by its path, which specifies its location in the file system. From a user's perspective, the Unix system structure can be categorized into the following directories: /bin: This directory contains essential executable files that are necessary for basic system operations. Common utilities such as ls, cp, and mkdir are located here. /sbin: Similar to /bin, /sbin contains essential system executables. However, these executables are typically used by the system administrator for tasks like system maintenance and troubleshooting. /usr: The /usr (Unix System Resources) directory contains a variety of user-related files and directories, including user binaries (/usr/bin), libraries (/usr/lib), and documentation (/usr/share/doc). /etc: The /etc (et cetera) directory stores system configuration files, such as configuration files for network settings, user authentication, and system startup scripts. /home: Each user on the system has a corresponding directory under /home, which serves as their home directory. Users can store personal files and create subdirectories within their respective home directories.

May 21, 2023
Unit - 2

Introduction to Kernel: The kernel is the core component of an operating system that acts as an intermediary between the hardware and the software running on a system. It provides essential services and manages the system's resources, including memory, processes, input/output (I/O), and file systems. The kernel is responsible for maintaining stability, security, and overall system integrity. Architecture of UNIX Operating System: The UNIX operating system follows a layered architecture that is organized into multiple components. The architecture consists of the following layers: Hardware Layer: This layer represents the physical hardware, including the CPU, memory, storage devices, and input/output devices. Kernel Layer: The kernel layer is responsible for managing system resources, handling hardware interactions, and providing essential services to user programs. It includes components such as process management, memory management, file system management, and device drivers. Shell Layer: The shell layer provides a command-line interface through which users interact with the system. It interprets user commands and communicates them to the kernel for execution. Utilities Layer: This layer consists of various system utilities and applications that are built on top of the kernel and shell. These utilities include compilers, editors, file manipulation tools, and network utilities.

May 21, 2023
Unit - 5

Structure of Process: A process is an instance of a running program in an operating system. It consists of several components that define its behavior and execution state. The main components of a process include: Process ID (PID): Each process is assigned a unique identifier called a Process ID. This ID is used by the operating system to identify and manage the process. Process State: A process can be in one of several states, including:a. Running: The process is currently being executed by the CPU.b. Ready: The process is waiting to be assigned to a CPU for execution.c. Blocked: The process is waiting for a particular event or resource to become available.d. Terminated: The process has finished its execution or has been explicitly terminated. Program Counter (PC): The Program Counter is a register that keeps track of the address of the next instruction to be executed in the process. Register Set: The Register Set consists of various CPU registers that store temporary data and execution context during the process execution. Memory Management Information: This includes information about the process's address space, such as the base address, limit, and memory segments (code, data, stack). Open Files: Processes may have open file descriptors that point to files or I/O devices opened by the process. Process Control Block (PCB): The PCB is a data structure maintained by the operating system for each process. It stores all the necessary information about a process, including its state, program counter, register values, memory management details, open file descriptors, and other relevant data.

May 20, 2023
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